Bidirectional Material Transport Device and Method with Single Beam and Double Lifting Points in the Construction Area of ​​Liquid Cargo Tank Level 0

Abstract

This invention belongs to the field of shipbuilding technology and discloses a bidirectional material transport device and method with a single beam and double lifting points in the construction area of ​​the zero layer of a liquid cargo tank. The device consists of a single beam, spliced ​​from two sections of I-beams. The beam is fixed to the top of the upper platform structure of the load layer along the material transport direction, with one end leading to the material turnover area and the other end extending above the opening of the hoisted object. Two electric trolley hoists are each equipped with a traveling actuator and a lifting actuator with encoder feedback, as well as a vehicle-mounted drive unit. The vehicle-mounted drive unit is electrically connected to the traveling actuator, lifting actuator, and remote control receiving module of the electric trolley hoists. The remote control receiving module includes a position module and a height module. The control system has a built-in hierarchical closed-loop calculation unit equipped with a dual-loop PID calculation module for position and height. The control system has two working modes: synchronous operation mode and independent adjustment mode. This invention occupies little space, is suitable for narrow construction sites, provides stable hoisting, and improves transportation efficiency and safety.

Description

Technical Field

[0001] This invention belongs to the field of shipbuilding technology, specifically relating to the construction process of LNG carrier containment systems, and particularly to a device and method for vertical bidirectional transportation of materials in the bottom 0 layer construction area of ​​a membrane-type LNG carrier cargo tank containment system. Background Technology

[0002] During the construction of the LNG carrier cargo tank containment system, multiple construction platforms need to be built along the depth of the cargo tank, and a dedicated freight elevator extending from the first floor to the top of the tank is required to facilitate the vertical transfer of construction materials between floors. However, due to limitations imposed by freight elevator safety regulations, car clearance dimensions, and interference from the platform's bottom structure, the freight elevator cannot directly reach the ground floor construction area, creating a persistent transportation blind spot. Furthermore, during the construction of the elevator's bottom support legs, the elevator cannot be used normally, potentially preventing timely delivery of installation materials to the bottom floor and impacting the continuity of construction.

[0003] Existing conventional solutions mainly rely on manual transport or secondary transshipment on the first floor, which suffers from low operational efficiency, difficulty in transporting ultra-long materials, high safety risks associated with high-altitude operations, occupation of core transportation resources, and disruption of the overall construction schedule. A double parallel beam hoisting scheme was proposed, but this scheme occupies a large space and is difficult to arrange within the load layer where storage capacity needs to be maximized; moreover, the space occupied by the double beam arrangement is more than three times the space of the hoisting opening, and material turnover is prone to safety hazards such as jamming and hoisting instability, which cannot meet the safe, stable, and efficient transportation requirements of the LNG ship's cargo tank level 0.

[0004] The marine hatch cover gantry crane disclosed in reference CN206345611U, including a complete gantry frame, two side legs, and double longitudinal guide rails on the deck, is bulky and cannot meet the needs of vertical bidirectional material transfer inside the hatch. The two electric hoists are each equipped with an independent transverse motor, relying solely on a unified control system for linkage, without a dedicated remote control receiving module; the two hoists cannot be individually fine-tuned for alignment, and the two-point lifting of long or irregularly shaped materials is prone to uneven force distribution and swaying, resulting in insufficient lifting stability. Summary of the Invention

[0005] To address the shortcomings and deficiencies of existing technologies, this invention provides a single-beam, double-lifting-point material transport device and method that occupies little space, is suitable for narrow construction sites, provides stable lifting, improves transportation efficiency and safety, and enables bidirectional transportation. It aims to solve the problem of blind spots in the 0th floor transportation of LNG cargo tanks, adapt to the needs of long-sized material transfer, does not interfere with the work on other construction floors, and ensures the continuous construction of LNG cargo tank containment systems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A bidirectional material transport device with a single beam and two lifting points for the construction area of ​​the liquid cargo tank at level 0, including a beam, two electric trolley hoists, a remote control receiving module and a remote control on the electric trolley hoists; the remote control is equipped with a control system; the remote control receiving module and the remote control are connected in communication; the two electric trolley hoists are slidably assembled on the beam. The beam is a single piece, spliced ​​from two sections of I-beams; the single beam is fixed to the top of the upper platform frame of the load layer along the material transport direction, with one end leading to the material turnover area and the other end extending to the top of the hoisting opening; The mechanical structures and remote control receiving modules of the two electric trolley hoists are completely independent. Each hoist is equipped with a walking actuator and a lifting actuator with encoder feedback, as well as an on-board drive unit. The on-board drive unit is electrically connected to the walking actuator and lifting actuator of the electric trolley hoist, and is also electrically connected to the remote control receiving module. The remote control receiving module includes a position module and a height module. The remote control receiving modules of the two electric trolley hoists are connected to the same remote controller for centralized control. The control system has a built-in hierarchical closed-loop calculation unit, which is configured with a dual-loop PID calculation module for position and height; the control system is set with two working modes: synchronous operation mode and independent adjustment mode. In synchronous operation mode, the remote controller sends the same target command to the two remote control receiving modules, and the position and height dual-loop PID calculation module outputs the same operation command to the vehicle drive unit, so that the two vehicle drive units drive their respective electric trolley hoists to move or lift synchronously. In independent adjustment mode, the remote control sends action commands only to the remote control receiver module of a single electric trolley hoist, while the other electric trolley hoist is locked. Only one vehicle-mounted drive unit drives one electric trolley hoist to move horizontally or vertically.

[0007] By adopting the above technical solution, the two electric trolley hoists have independent mechanical structures and remote control receiving modules, and are centrally controlled by a remote controller. The control system is equipped with a dual-loop PID calculation module for position and height, employing a hierarchical closed-loop algorithm. In synchronous operation mode, the control system outputs the same operating commands to the on-board drive unit. In independent adjustment mode, only the movement of a single electric trolley hoist is controlled to adjust the height difference of the lifting points. Full-range limit protection ensures timely braking when exceeding limits, providing flexible, safe, and reliable operation.

[0008] Preferably, the position and height dual-loop PID calculation module is a cascaded closed-loop structure, with the outer loop being the position loop PID and the inner loop being the height loop PID. The position loop PID calculates the position deviation based on the target position sent by the remote controller and the actual position fed back by the encoder, and outputs the target height as the setpoint of the height loop PID. The height loop PID calculates the height deviation based on the target height and the actual running height collected by the encoder, outputs the drive control quantity, and adjusts the output torque of the motor in the lifting actuator.

[0009] Preferably, the remote control is equipped with a synchronous operation button and a single-unit independent adjustment button. The button signals are used to output switching instructions between synchronous operation mode and independent adjustment mode to the remote control receiving module, so as to realize synchronous operation and independent adjustment.

[0010] Preferably, the splicing joint is located in the middle of the top of the upper platform structure, and fixed clamping plate assemblies are set on the left and right sides of the joint; the beam is installed on the top of the upper platform structure through the fixed clamping plate assemblies.

[0011] Preferably, the fixing clamp assembly includes a clamping bolt, an upper clamp, and a lower clamp. The inner surfaces of the upper and lower clamps are both in contact with the surface of the upper flange of the I-beam. The lower clamp is L-shaped and includes a vertical plate and a support plate, which are integrally formed.

[0012] Preferably, the clamp bolt is U-shaped and fits against the top of the upper platform frame; an upper clamping plate is installed on the two vertical plates, and the clamp bolt passes through the cover plate, the upper clamping plate and the lower clamping plate after it grips the top of the upper platform frame, and is fastened with fasteners.

[0013] Preferably, a limiting block is provided at the end of the beam.

[0014] Transportation method for a single-beam, double-lifting-point, two-way material transport device in the construction area of ​​the liquid cargo tank's 0th floor. S1. Equipment Layout: Two sections of I-beams are fixed to the top of the upper platform frame of the load layer along the material transport direction to form a beam. One end of the beam is connected to the material turnover area and the other end extends to the top of the hoisting opening. Two electric trolley hoists with independent mechanical structures are arranged at intervals along the axial direction of the beam. Two remote control receiving modules are connected to the control system on the remote control to achieve synchronous linkage or independent fine-tuning control. S2. Material lowering and transportation: The materials to be transported are hung at two points in the material turnover area. The remote control is operated to press the synchronous operation button, and the control system switches to synchronous operation mode. The control system outputs the same target command to two independent remote control receiving modules. The position and height of each electric trolley hoist are calculated independently by the dual-loop PID calculation module. The two electric trolley hoists move synchronously to the top of the hoisting opening, and are lowered synchronously to the 0-floor construction area before being unhooked, completing the material entry. S3. Waste material and tool lifting and transportation: The waste material or tool on the 0th layer is hung at two points and lifted synchronously over the opening height of the hoisting object. The electric trolley hoist is controlled to move synchronously to the material turnover area and then the hook is unhooked to complete the lifting and transfer of waste material or tool out of the cabin. S4. Independent Leveling and Correction: When the hoisted materials, waste, or tools are tilted or there is a height difference between the two hoisting points, the remote control can be used to independently adjust the hoisting point by pressing the button on the hoisting point. The control system will switch to independent adjustment mode, and the remote control will only send action commands to the hoisting point. The other electric trolley hoist will be locked and braked. The hoisting point height will be adjusted by the independent height loop PID of the hoisting point to correct the posture of the materials, waste, or tools.

[0015] By adopting the above technical solution, the beam structure composed of spliced ​​I-beams is equipped with two electric trolley hoists with completely independent mechanical structures and remote control receiving modules. Each electric trolley hoist has a traveling actuator, a lifting actuator, and an on-board drive unit. On the one hand, the spacing between hoists can be flexibly arranged as needed, reducing local concentrated loads on the I-beams and resulting in better stress conditions for the I-beams as the beam structure. During maintenance, one electric trolley hoist can be stopped independently without affecting the operation of the other. On the other hand, the control system features a layered closed-loop design, with synchronous operation and independent adjustment of each hoist operating independently without interference. When materials, waste materials, or tools are tilted during material lowering and transportation, or waste material or tool lifting and transportation, real-time unilateral leveling can be performed, ensuring stable hoisting. It can safely transport plates with lengths of 3.5m and above, significantly improving the safety of hoisting operations and adapting to the hoisting of various components of different lengths and centers of gravity. Moreover, there is no need to break down the hoisting and transportation process, increasing transportation efficiency by more than 10 times compared to manual transportation, with a single long material transportation time not exceeding 2 minutes.

[0016] Preferably, the rated lifting capacity of a single electric trolley hoist is 1t, the total rated lifting capacity is 2t, and the distance between lifting positions is no more than 3000mm, so as to realize the dual-point balanced lifting of long materials.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention adopts a single beam arrangement, which occupies only 1.5m of passage space, is compatible with the load layer 11 and the standard hanging object opening size, has strong site adaptability, and does not require modification of the existing elevator.

[0018] 2. This application achieves synchronous operation and independent adjustment through a remote control with an integrated synchronous operation button, a vehicle-mounted drive unit with two electrically isolated circuits, and the traveling and lifting actuators of two independent electric trolley hoists with encoder feedback. The remote control is equipped with synchronous operation and independent adjustment buttons. The control system switches signals according to the synchronous operation mode and the independent adjustment mode. In the synchronous operation mode, the same action command is sent to both electric trolley hoists. In the independent adjustment mode, the action signal is sent only to the designated electric trolley hoist, and the other electric trolley hoist is locked. With the position and speed feedback of each electric trolley hoist, it takes into account both synchronous lifting and precise single-sided adjustment functions.

[0019] 3. The beam structure composed of spliced ​​I-beams of this invention is equipped with two electric trolley hoists with completely independent mechanical structures and remote control receiving modules. Each electric trolley hoist has a walking actuator, a lifting actuator, and an on-board drive unit. On the one hand, the spacing between hoists can be flexibly arranged as needed, reducing local concentrated loads on the I-beams and resulting in better stress conditions for the I-beams as the beam structure. During maintenance, one electric trolley hoist can be stopped independently without affecting the operation of the other. On the other hand, the control system features a layered closed-loop design, with synchronous operation and independent adjustment of each hoist operating independently without interference. When materials, waste materials, or tools are tilted during material lowering and transportation or waste material and tool lifting and transportation, real-time unilateral leveling can be performed, ensuring stable hoisting. It can safely transport plates with lengths of 3.5m and above, significantly improving the safety of hoisting operations and adapting to the hoisting of various components of different lengths and centers of gravity. Moreover, there is no need to break down the hoisting and transportation process, increasing transportation efficiency by more than 10 times compared to manual transportation, with a single long material transportation time not exceeding 2 minutes.

[0020] 4. This invention allows for fully remote operation, eliminating the need for construction personnel to enter the risky areas near edges or below suspended objects, thus ensuring safety during high-altitude operations.

[0021] 5. This invention relies on the existing load layer upper platform structure for reverse top arrangement, resulting in low implementation cost per ship, no occupation of the ship's main transportation resources, and no interference with construction on other layers. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of a beam structure mounted on the top of the upper platform frame of the present invention. Figure 3 This is a front view of the electric trolley hoist of the present invention; Figure 4 This is a side view of the electric trolley hoist of the present invention; Figure 5 This is a schematic diagram of the installation of the fixing clamp assembly on the beam body according to the present invention; Figure 6 This is an overall layout diagram of the transportation device of the present invention; Figure 7 This is a plan view of the load layer of the present invention; Figure 8 This is a schematic diagram of the transportation method of the present invention.

[0023] Drawing numbers: 1—Upper wing plate, 2—Beam body, 3—Electric pulley hoist, 4—Lifting opening, 5—0th floor construction area, 6—Material turnover area, 7—Traveling actuator, 8—Lifting actuator, 9—Vehicle-mounted drive unit, 10—Fasteners, 11—Load layer, 12—Upper clamp plate, 13—Lower clamp plate, 14—Vertical plate, 15—Plate, 20—Lifting position spacing, 22—Fixed clamp plate assembly, 23—Clamping bolt, 24—Upper platform frame top, 25—Limiting block, 33—Remote control receiver module, 331—Position module, 332—Height module. Detailed Implementation

[0024] like Figure 1-2 As shown, the bidirectional material transport device with a single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0 includes a beam 2, two electric trolley hoists 3, a remote control receiving module 33 on the electric trolley hoists 3, and a remote controller; the remote controller is equipped with a control system; the remote control receiving module 33 and the remote controller are communicatively connected. The two electric trolley hoists 3 are slidably mounted on the beam 2.

[0025] Beam 2 is a single beam made of SUS material with dimensions of 180×80×8, with a total length of 12m, and is spliced ​​from two 6m sections of I-beams. The single beam 2 is extended and fixed to the top 24 of the upper platform frame of the load layer 11 along the material transportation direction, with one end leading to the material turnover area 6 and the other end extending above the hoisting opening 4.

[0026] like Figure 3-4 As shown, the mechanical structures and remote control receiving modules of the two electric trolley hoists 3 are completely independent. Each is equipped with a walking actuator 7 with encoder feedback, a lifting actuator 8, and an on-board drive unit 9. The on-board drive unit 9 is electrically connected to the walking actuator 7 and the lifting actuator 8 of the electric trolley hoist 3, and is also electrically connected to the remote control receiving module 33. The remote control receiving module 33 includes a position module 331 and a height module 332. The remote control receiving modules 33 of the two electric trolley hoists 3 are connected to the same remote controller to achieve centralized control.

[0027] The control system has a built-in hierarchical closed-loop calculation unit, which is equipped with a dual-loop PID calculation module for position and height; the control system is set with two working modes: synchronous operation mode and independent adjustment mode.

[0028] In synchronous operation mode, the remote controller sends the same target command to both remote control receiver modules 33, and the position and height dual-loop PID calculation module outputs the same operation command to the vehicle-mounted drive unit 9, causing the two vehicle-mounted drive units 9 to drive their respective electric trolley hoists 3 to move or lift synchronously. In independent adjustment mode, the remote controller only sends the action command to the remote control receiver module 33 of one electric trolley hoist 3, while the other electric trolley hoist 3 is locked, and only one vehicle-mounted drive unit 9 drives one electric trolley hoist 3 to move or lift independently.

[0029] The two electric trolley hoists 3 in this application have independent mechanical structures and remote control receiving modules, and are centrally controlled by a remote controller. The control system is equipped with a dual-loop PID calculation module for position and height, and adopts a hierarchical closed-loop algorithm. In synchronous operation mode, the control system outputs the same operating command to the on-board drive unit 9. In independent adjustment mode, only one electric trolley hoist 3 is controlled to adjust the height difference of the lifting points. Full-range limit protection, timely braking when exceeding the limit, flexible operation and safe and reliable operation. This application adopts a single beam arrangement, occupying only 1.5m of passage space, adapting to the load layer 11 and the standard opening size of the hoisted object, with strong site adaptability and no need to modify the existing elevator.

[0030] The position and height dual-loop PID calculation module is a cascaded closed-loop structure, with the outer loop being the position loop PID and the inner loop being the height loop PID. The position loop PID calculates the position deviation based on the target position sent by the remote controller and the actual position fed back by the encoder, and outputs the target height as the setpoint of the height loop PID. The height loop PID calculates the height deviation based on the target height and the actual running height collected by the encoder, outputs the drive control quantity, and adjusts the output torque of the motor in the lifting actuator 8.

[0031] The remote control is equipped with a synchronous operation button and a single-unit independent adjustment button. Through the button signal, it outputs the switching command between synchronous operation mode and independent adjustment mode to the position module 331 and the height module 332 of the remote control receiver module 33, so as to realize synchronous operation and independent adjustment.

[0032] The splicing joint is located in the middle of the upper platform frame's inverted top 24, and fixing clamp assemblies 22 are respectively installed on the left and right sides of the joint. The beam 2 is installed on the upper platform frame's inverted top through the fixing clamp assemblies 22.

[0033] Two H-beams are spliced ​​together by clamping with bolts 23 and fixing clamping plate assemblies 22. The splicing joint is located in the center of the top of the same upper platform frame. Bolts 23 and fixing clamping plate assemblies 22 are respectively arranged on the left and right sides of the joint to form a limiting structure, constraining the H-beam 2 from multiple directions and preventing horizontal slippage and torsional deformation of the spliced ​​section of the beam 2. During splicing, the coaxiality requirement is that after splicing, the upper and lower flanges and webs of the two H-beams must be kept coaxially aligned. The butt joint gap requirement is that the gap between the end faces of the two H-beams should be controlled within 2mm. The misalignment control requirement is that the misalignment at the joint of the flanges and webs should not exceed 1mm. The clamping assembly requirement is that the upper and lower fixing clamps are respectively attached to and cover both sides of the upper flange 1 of the H-beam 2, and are fastened with bolts 23 to form a ring clamping structure. The clamping plate surface is completely attached to the base material of the upper flange 1 to ensure uniform clamping force and no local gaps or warping. Arrangement requirements: The upper and lower fixed clamps are arranged symmetrically along the butt joint. The shape of the upper and lower fixed clamps is compatible with the upper flange 1 of the I-beam 2. There are no protruding structures that would interfere with the normal movement of the trolley.

[0034] like Figure 5 As shown, the fixed clamping plate assembly 22 includes a clamping bolt 23, an upper clamping plate 12 and a lower clamping plate 13. The inner surfaces of the upper clamping plate 12 and the lower clamping plate 13 are both in contact with the surface of the upper flange 1 of the I-beam. The lower clamping plate 13 is L-shaped and includes a vertical plate 14 and a support plate 15. The vertical plate 14 and the support plate 15 are integrally formed.

[0035] The clamp bolt is U-shaped and fits against the top of the upper platform frame; the two vertical plates 14 are covered with upper clamping plates 12, and after the clamp bolt hugs the top of the upper platform frame, it passes through the cover plate, upper clamping plate 12 and lower clamping plate 13 and is fastened with fasteners 10.

[0036] This application provides symmetrically arranged fixing clamp assemblies 22 at the joint positions of the beam body 2. The fixing clamp assemblies 22 are fitted and wrapped around both sides of the upper flange 1 of the I-beam, and consist of two structures: an upper clamp 12 and a lower clamp 13. The structure offers strong adaptability and high clamping precision. The upper clamp 12 is an integral, flat plate steel structure with a smooth surface. The lower clamp 13 is an L-shaped plate steel structure with a milled surface; the mating surface is precision milled to ensure a tight, gapless fit. All clamp surfaces have pre-drilled bolt holes for locking and fixing via clamping bolts 23. The entire set of fixing plates is symmetrically arranged along the joint gap of the I-beams, and works in conjunction with the matching clamp bolts 23 to form a ring-shaped clamping and limiting structure, locking the two jointed I-beams. This effectively restrains and counteracts the horizontal slippage, lateral displacement, and torsional deformation of the I-beams as beam 2 during the movement of the electric trolley hoist 3, ensuring that the upper flange 1, web plate, and lower flange of the two I-beams at the splicing position always remain coaxially aligned, precisely controlling the joint gap and misalignment, and meeting the requirements for high-precision assembly and use.

[0037] The overall outline of the fixed clamping plate assembly 22 is precisely matched to the shape of the upper flange 1 of the I-beam. The plate surface is completely attached to the surface of the base material of the upper flange 1 of the I-beam, with no protrusions or interference structures. It can work with the clamp to form a multi-dimensional constraint system, providing all-round positioning and fixation for the two spliced ​​I-beam sections. The fixed clamping plate assembly 22 adopts a clamping method with a large-area surface contact with the upper flange 1 of the I-beam, achieving uniform force distribution and completely avoiding the problems of local compression and deformation damage to the base material caused by traditional single-point clamping. This effectively improves the overall bending and shear resistance of the I-beam splice joint, adapting to the alternating loads and impact loads generated by the reciprocating movement of the electric trolley hoist 3, and significantly improving the stability and safety of the I-beam when running as a track. The fixed clamping plate assembly 22 adopts a pure bolt-mounted detachable assembly structure, requiring no welding work throughout the process, without damaging the base material of the I-beam, and fully preserving the original mechanical properties of the beam. It is also suitable for on-site segmented hoisting and splicing installation, with high assembly efficiency; the fixed clamping plate assembly 22 can be quickly disassembled later, which facilitates the inspection, maintenance and replacement of the I-beam splicing position and the I-beam used as the track, making it highly practical and versatile.

[0038] Limiting blocks 25 are installed at the ends of beam 2 to limit the travel limit of electric trolley hoist 3, prevent electric trolley hoist 3 from moving beyond its range, prevent electric trolley hoist 3 from derailing from the end of I-beam 2, and ensure the safety of hoisting operations.

[0039] like Figure 6-8 As shown, this describes the transportation method of a bidirectional material transport device with a single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0. S1. Equipment Layout: Two sections of I-beams are fixed to the upper platform frame of the load layer 11 along the material transport direction to form a beam 2. One end of the beam 2 is connected to the material turnover area 6, and the other end extends to the top of the hoisting opening 4. Two electric trolley hoists 3 with independent mechanical structures are arranged at intervals along the axial direction of the beam 2. Two remote control receiving modules 33 are connected to the control system on the remote control to achieve synchronous linkage or independent fine-tuning control. S2. Material lowering and transportation: The materials to be transported are hung at two points in the material turnover area 6. The remote control is operated to press the synchronous operation button, and the control system is switched to synchronous operation mode. The control system outputs the same target command to two independent remote control receiving modules 33. The position and height of each electric trolley hoist 3 are calculated independently by the dual-loop PID calculation module. The two electric trolley hoists 3 move synchronously to the top of the hoisting opening 4, and are lowered synchronously to the 0th floor construction area 5 before being unhooked, completing the material entry. S3. Material lifting and transportation: The waste or tools on layer 0 are hung at two points and simultaneously lifted over the height of the hoisting opening 4. The electric trolley hoist 3 is controlled to move synchronously to the material turnover area 6 and then the hook is removed to complete the lifting and transfer of waste or tools out of the cabin. S4. Independent Leveling and Correction: When the hoisted materials, waste, or tools are tilted or there is a height difference between the two hoisting points, the remote control can be used to independently adjust the hoisting point by pressing the button on the hoisting point. The control system will switch to independent adjustment mode, and the remote control will only send action commands to the hoisting point. The other electric trolley hoist 3 will be locked and braked. The hoisting point height will be adjusted by the independent height loop PID of the hoisting point to correct the posture of the materials, waste, or tools.

[0040] The beam body 2, composed of spliced ​​I-beams, is equipped with two electric trolley hoists 3, each with a completely independent mechanical structure and remote control receiving module. Each electric trolley hoist 3 has a walking actuator 7, a lifting actuator 8, and a vehicle-mounted drive unit 9. On one hand, the hoisting position spacing 20 can be flexibly arranged as needed, reducing localized concentrated loads on the I-beams 2, resulting in better stress conditions for the I-beams as the beam body. During maintenance, one electric trolley hoist 3 can be stopped independently without affecting the operation of the other. On the other hand, the control system features a layered closed-loop design, ensuring that synchronous operation and independent adjustment of each hoist do not interfere with each other. When materials, waste, or tools are tilted during material lowering and transportation, or waste material or tool lifting and transportation, real-time unilateral leveling can be achieved, ensuring stable hoisting. It can safely transport plates 3.5m and longer, significantly improving the safety of hoisting operations and adapting to the hoisting of various components of different lengths and centers of gravity. Furthermore, there is no need to break down the hoisting and transportation process, increasing transportation efficiency by more than 10 times compared to manual transportation, with a single long material transport taking no more than 2 minutes.

[0041] The position and speed signals of the two hoists are collected in real time throughout the transportation process. When either hoist triggers the limit threshold, the control system drives the on-board drive unit 9 of the corresponding electric trolley hoist 3 to brake immediately, and at the same time drives the other electric trolley hoist 3 to lock.

[0042] Each electric trolley hoist has a rated lifting capacity of 1t and a total rated lifting capacity of 2t. The axial lifting position spacing is no more than 3000mm, enabling dual-point balanced lifting of long materials.

[0043] This invention employs a method where a single I-beam 2, composed of two I-beam sections coaxially joined together, is installed on the upper platform frame 24 of the load layer 11. Two sets of synchronously controllable electric pulley hoists 3 are then installed, forming a single-beam, double-lifting-point hoisting structure. This allows for a two-way transportation process: material lowering into the site and waste material and equipment lifting out of the hold, thus facilitating both material entry and waste removal. The device occupies minimal space, requiring only a 1.5m passageway width, making it suitable for narrow spaces and standard lifting openings. The hoisting is stable, safe, and efficient, increasing transportation efficiency by more than 10 times compared to manual transfer. It completely solves the problem of blind spots in the 0th-floor transportation system, does not interfere with operations on other construction layers, and meets the continuous construction requirements of LNG ship containment systems.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bidirectional material transport device with a single beam and two lifting points for the construction area of ​​the liquid cargo tank at level 0, comprising a beam, two electric trolley hoists, a remote control receiving module and a remote control on the electric trolley hoists; the remote control is equipped with a control system; the remote control receiving module and the remote control are communicatively connected; the two electric trolley hoists are slidably mounted on the beam; characterized in that: The beam is a single piece, spliced ​​from two sections of I-beams; the single beam is fixed to the top of the upper platform frame of the load layer along the material transport direction, with one end leading to the material turnover area and the other end extending above the opening of the hoisting object; The two electric trolley hoists have independent mechanical structures and remote control receiver modules. Each hoist is equipped with a walking actuator and a lifting actuator with encoder feedback, as well as an on-board drive unit. The on-board drive unit is electrically connected to the walking actuator and lifting actuator of the electric trolley hoist, and is also electrically connected to the remote control receiver module. The remote control receiver module includes a position module and a height module. The remote control receiver modules of the two electric trolley hoists are connected to the same remote controller for centralized control. The control system has a built-in hierarchical closed-loop calculation unit, which is configured with a dual-loop PID calculation module for position and height; the control system is set with two working modes: synchronous operation mode and independent adjustment mode.

2. The bidirectional material transport device with single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0, as described in claim 1, is characterized in that: The position and height dual-loop PID calculation module is a cascaded closed-loop structure, with the outer loop being the position loop PID and the inner loop being the height loop PID.

3. The bidirectional material transport device with single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0, as described in claim 1, is characterized in that: The remote control is equipped with a synchronous operation button and an independent adjustment button for each unit.

4. The bidirectional material transport device with single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0, as described in claim 1, is characterized in that: The splicing joint is located in the middle of the top of the upper platform structure, and fixed clamping plate assemblies are set on the left and right sides of the joint respectively; the beam is installed on the top of the upper platform structure through the fixed clamping plate assemblies.

5. The bidirectional material transport device with single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0, as described in claim 4, is characterized in that: The fixing clamp assembly includes a clamping bolt, an upper clamp, and a lower clamp. The inner surfaces of the upper and lower clamps are both in contact with the surface of the upper flange of the I-beam. The lower clamp is L-shaped and includes a vertical plate and a support plate, which are integrally formed.

6. The bidirectional material transport device with single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0, as described in claim 5, is characterized in that: The clamp bolt is U-shaped and fits against the top of the upper platform frame; an upper clamping plate is installed on the two vertical plates, and the clamp bolt passes through the cover plate, the upper clamping plate and the lower clamping plate after it hugs the top of the upper platform frame, and is fastened with fasteners.

7. The bidirectional material transport device with single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0, as described in claim 1, is characterized in that: A limiting block is provided at the end of the beam.

8. A transportation method based on the bidirectional material transportation device with single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0 as described in any one of claims 1-7, characterized in that: Includes the following steps: S1. Equipment Layout: Two sections of I-beams are fixed to the top of the upper platform frame of the load layer along the material transport direction to form a beam. One end of the beam is connected to the material turnover area and the other end extends to the top of the hoisting opening. Two electric trolley hoists with independent mechanical structures are arranged at intervals along the axial direction of the beam. Two remote control receiving modules are connected to the control system on the remote control to achieve synchronous linkage or independent fine-tuning control. S2. Material lowering and transportation: The materials to be transported are hung at two points in the material turnover area. The remote control is operated to press the synchronous operation button, and the control system switches to synchronous operation mode. The control system outputs the same target command to two independent remote control receiving modules. The position and height of each electric trolley hoist are calculated independently by the dual-loop PID calculation module. The two electric trolley hoists move synchronously to the top of the hoisting opening, and are lowered synchronously to the 0-floor construction area before being unhooked, completing the material entry. S3. Waste material and tool lifting and transportation: The waste material or tool on the 0th layer is hung at two points and lifted synchronously over the opening height of the hoisting object. The electric trolley hoist is controlled to move synchronously to the material turnover area and then the hook is unhooked to complete the lifting and transfer of waste material or tool out of the cabin. S4. Independent Leveling and Correction: When the hoisted materials, waste, or tools are tilted or there is a height difference between the two hoisting points, the remote control can be used to independently adjust the hoisting point by pressing the button on the hoisting point. The control system will switch to independent adjustment mode, and the remote control will only send action commands to the hoisting point. The other electric trolley hoist will be locked and braked. The hoisting point height will be adjusted by the independent height loop PID of the hoisting point to correct the posture of the materials, waste, or tools.

9. The transportation method of the bidirectional material transportation device with single beam and double lifting points in the construction area of ​​the liquid cargo tank at level 0 according to claim 8, characterized in that: The rated lifting capacity of a single electric trolley hoist is 1t, the total rated lifting capacity is 2t, and the distance between lifting positions is no more than 3000mm, so as to realize the dual-point balanced lifting of long materials.

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