Integral hoisting method for rear girder and machine room components of a bridge-type ship unloader

Abstract

The present invention discloses an overall hoisting method for the rear girder and machine room components of a bridge-type ship unloader, which includes the following steps: S1, install the rear girder component at a low altitude position; S2, after arranging and installing the machine room component on the ground, hoist it above the rear girder component for installation; S3, calculate the overall center of gravity position and distributed load after the installation of the rear girder component and the machine room component, and obtain the type and installation position of the hoisting lugs; S4, after the installation of the hoisting lugs is completed, select a hoisting tool and a gantry crane to hoist the whole of the installed rear girder component and the machine room component to the installation position. The present invention solves the difficulties and disadvantages of the prior art by optimizing the general assembly process flow and method.

Description

Technical Field

[0001] The present invention relates to the general assembly technology of large equipment, and more specifically, to an overall hoisting method for the rear girder and the machine room assembly of a bridge type ship unloader. Background Art

[0002] Restricted by its structural form, the traditional bridge type grab ship unloader has a large lifting tonnage and limited hoisting point positions. Therefore, the traditional general assembly method for the rear girder and the machine room is that the machine room assembly needs to be pre-assembled with the rear girder assembly on the ground in advance. After pre-assembly, the machine room and the rear girder are disassembled. After the general assembly of the rear girder and the portal frame assembly is completed, the machine room assembly is hoisted in place. This scheme requires the machine room to be hoisted multiple times, and it is necessary to position the machine room at a high altitude and install the connecting bolts with the support. There are disadvantages such as low work efficiency, high equipment occupancy rate, and long general assembly cycle. Summary of the Invention

[0003] Aiming at the above-mentioned defects existing in the prior art, the purpose of the present invention is to provide an overall hoisting method for the rear girder and the machine room assembly of a bridge type ship unloader, and solve the difficulties and disadvantages of the prior art by optimizing the general assembly process flow and method.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] An overall hoisting method for the rear girder and the machine room assembly of a bridge type ship unloader, comprising the following steps:

[0006] S1. Install the rear girder assembly in place at a low altitude;

[0007] S2. After arranging the machine room assembly on the ground, hoist it above the rear girder assembly for installation;

[0008] S3. Calculate the overall center of gravity position and distributed load after the installation of the rear girder assembly and the machine room assembly, and obtain the type and installation position of the hoisting lugs;

[0009] S4. After the installation of the hoisting lugs is completed, select a hoisting tool and a gantry crane to hoist the whole installed rear girder assembly and the machine room assembly to the installation position.

[0010] Preferably, the step S3 further includes:

[0011] S31. Use a finite element model to calculate the overall center of gravity position and distributed load after the installation of the rear girder assembly and the machine room assembly, select the hoisting point installation position to draw a hoisting diagram, and determine that the hoisting method of the rear girder assembly and the machine room assembly conforms to the load curve of the gantry crane according to the general assembly site layout;

[0012] S32. Select a lifting lug according to the weight distribution of the rear girder assembly and the machine room assembly, and calculate the structural strength of the lifting lug.

[0013] S33. Adjust the positions of the small parts in the rear girder assembly and the machine room assembly to optimize the lifting drawing.

[0014] S34. According to the lifting drawing, check the force on the lifting lug, the deformation of each component, and the load capacity of the portal crane.

[0015] Preferably, the finite element model adopts BEAM44 elements and MASS21 elements.

[0016] Preferably, the finite element model adopts a magnification factor of 1.2; that is

[0017] The overall gravitational acceleration g for the installation of the rear girder assembly and the machine room assembly is g = 1.2 × 9.8 kg / m 3 .

[0018] Preferably, an insert type lifting lug is adopted on the rear girder assembly.

[0019] Preferably, in step S3, the type and installation position of the lifting lug are obtained as follows:

[0020] Step a. First, calculate the weight and center of gravity of each single component one by one. Then, taking the end position of the rear girder as the reference point, calculate the center of gravity and weight of the overall lifting component according to the center of gravity and weight of each single component: weight × moment arm = moment.

[0021] Step b. After obtaining the result of the calculation of the center of gravity position of the overall component, offset from the center of gravity position to both sides, and find suitable lifting lug installation positions on the rear girder structure.

[0022] Calculate the force on each lifting lug, that is, the distributed load, according to the distances L1 and L2 from the two lifting lugs to the center of gravity position: F1 + F2 = G, F1 * L1 = F2 * L2, where F1 and F2 are the forces on the lifting lugs and G is the total weight of the component. Then, design the structural form of the lifting lug and select the appropriate type of sling according to the lifting point distributed loads F1 and F2.

[0023] The overall lifting method for the rear girder and the machine room assembly of a bridge type ship unloader provided by the present invention has the following beneficial effects:

[0024] 1) Effectively shorten the total assembly cycle and save valuable time wealth;

[0025] 2) Reduce the number of liftings of the machine room, effectively reduce the amount of lifting operations and the number of times of using the portal crane, and relieve the tense situation of the use of lifting equipment;

[0026] 3) After the rear girder is lifted, the machine room is assembled in place, reducing the risk of a large number of personnel working at height in cross-operation and effectively improving the working efficiency of workers;

[0027] 4) The overall assembly of the rear girder assembly and the machine room maximizes the actual load capacity of the portal crane and can significantly improve the usage efficiency of the portal crane;

[0028] 5) After the machine room is hoisted once, it is no longer necessary to place it on the ground tire rack, which can significantly save the number of times of site use and relieve the pressure of site use. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic flow chart of the overall hoisting method of the rear girder and the machine room assembly of the present invention;

[0030] Figure 2 is a schematic diagram of step S in the overall hoisting method of the rear girder and the machine room assembly of the present invention;

[0031] Figure 3 is a schematic diagram of step S in the overall hoisting method of the rear girder and the machine room assembly of the present invention;

[0032] Figure 4 is Figure 3 a top view schematic diagram of. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] In order to better understand the above technical solutions of the present invention, the technical solutions of the present invention will be further described below with reference to the drawings and embodiments.

[0034] Combined with Figure 1 shown, an overall hoisting method for the rear girder and the machine room assembly of a bridge-type ship unloader provided by the present invention includes the following steps:

[0035] S1. Install the rear girder assembly 100 in a low-altitude position, mainly installing components such as the trapezoidal frame, main trolley, tow rope trolley, driver's cab, ladder platform, front tie rod, safety hook and their accessories in place;

[0036] S2. Assemble the machine room assembly 200 on the ground. After mainly installing accessories such as the pitching mechanism, hoisting mechanism, electrical control cabinet, indoor maintenance crane, ladder platform, etc., hoist it above the rear girder assembly 100 for installation, as Figure 2 shown;

[0037] S3. Calculate the overall center of gravity position and distributed load after the installation of the rear girder assembly 100 and the machine room assembly 200, and obtain the type and installation position of the lifting lugs 300. The lifting lugs 300 are integrally provided with the main girder of the rear girder assembly 100. Four plug-in lifting lugs 300 are installed on the main girder, and the main board of the lifting lugs 300 is butted against the box web of the main girder;

[0038] S4. After the lifting lugs 300 and all components and accessories are installed, select the lifting tools (wire ropes 1, shackles, etc.) and two gantry cranes 2 to hoist the integral of the rear girder assembly 100 and the machine house assembly 200 installed to the installation position.

[0039] The above step S3 further includes:

[0040] S31. Use the finite element model to calculate the overall center of gravity position and distributed load after the installation of the rear girder assembly 100 and the machine house assembly 200, select the hoisting point installation position to draw the hoisting diagram, and determine that the hoisting method of the rear girder assembly 100 and the machine house assembly 200 conforms to the load curve of the gantry crane according to the general assembly site layout;

[0041] S32. Select the lifting lugs 300 according to the weight distribution of the rear girder assembly 100 and the machine house assembly 200, and calculate the structural strength of the lifting lugs 300 to ensure that the hoisting deformation of the assembled components is within the controllable range;

[0042] S33. Adjust the positions of each small part in the rear girder assembly 100 and the machine house assembly 200, optimize the hoisting diagram, and design the hoisting tooling parts;

[0043] S34. According to the hoisting diagram, check the stress of the lifting lugs 300, the deformation of each component, and the load of the gantry crane 2.

[0044] Establish a finite element model according to the overall of the rear girder assembly 100 and the machine house assembly 200 after installation. The finite element model uses BEAM44 elements and MASS21 elements.

[0045] The total self-weight of the overall of the rear girder assembly 100 and the machine house assembly 200 after installation is 745T. Components such as the machine house, hoisting and slewing mechanisms, main trolley, and driver's cab are added to the corresponding parts in the form of mass points. When calculating, the finite element model uses a magnification factor of 1.2. Therefore, the gravitational acceleration g of the overall of the rear girder assembly 100 and the machine house assembly 200 installed is 1.2×9.8 kg / m 3 .

[0046] In step S3, the types and installation positions of the lifting lugs are obtained as follows:

[0047] Step a. First, calculate the weight and center of gravity of each single component one by one, then take the position of the rear girder end as the reference point, and then calculate the center of gravity and weight of the overall hoisting components according to the center of gravity and weight of each single component: weight × moment arm = moment;

[0048] Step b. After obtaining the result of the overall component center of gravity position calculation, offset from the center of gravity position to both sides to find suitable hoisting lug installation positions on the rear girder structure;

[0049] Calculate the force on each lifting lug, i.e., the distributed load, according to the distances L1 and L2 from the lifting lugs on both sides to the center of gravity: F1 + F2 = G, F1 * L1 = F2 * L2, where F1 and F2 are the forces on the lifting lugs and G is the total weight of the component. Then, design the structural form of the lifting lug and select the appropriate type of sling according to the distributed loads F1 and F2 at the lifting points.

[0050] The installation of the lifting lug position needs to consider: (1) The installation position of the lifting lug should avoid the joint position of the component; (2) After the slings and shackles are configured according to the lifting lug position, they are not allowed to interfere with the overall component.

[0051] From the above data, it can be seen that the maximum stress of the rear girder component 100 structure is 170 MP, and the maximum stress of the lifting lug 300 and the surrounding steel structure is 164 Mpa. Based on the above analysis, it is determined that the strength of the lifting lug 300 and the steel structure of the ship unloader itself meets the overall lifting plan.

[0052] Those of ordinary skill in the art in this technical field should recognize that the above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. As long as it is within the scope of the spirit of the present invention, any changes and modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for overall hoisting of the rear girder and the machine room assembly of a bridge-type ship unloader, characterized in that, It includes the following steps: S1. Complete the installation of the rear girder assembly at a low altitude position; S2. After arranging and installing the machine room assembly on the ground, hoist it above the rear girder assembly for installation; S3. Calculate the overall center of gravity position and distributed load after the installation of the rear girder assembly and the machine room assembly, obtain the type and installation position of the lifting lugs, integrally set the lifting lugs with the main beam of the rear girder assembly, install four plug-in lifting lugs on the main beam, and butt the main board of the lifting lug with the box web of the main beam; S4. After the installation of the lifting lugs and all components and accessories is completed, select a lifting tool and a gantry crane to hoist the whole of the rear girder assembly and the machine room assembly to the installation position; The step S3 further includes: S31. Use a finite element model to calculate the overall center of gravity position and distributed load after the installation of the rear girder assembly and the machine room assembly, select the installation position of the lifting points to draw a lifting diagram, and determine that the lifting method of the rear girder assembly and the machine room assembly conforms to the load curve of the gantry crane according to the general assembly site layout; S32. Select the lifting lugs according to the weight distribution of the rear girder assembly and the machine room assembly, and calculate the structural strength of the lifting lugs; S33. Adjust the positions of each small part in the rear girder assembly and the machine room assembly to optimize the lifting diagram; S34. According to the lifting diagram, check the stress of the lifting lugs, the deformation of each component, and the load of the gantry crane; The finite element model adopts a magnification factor of 1.2; that is The overall gravitational acceleration g at which the rear beam assembly is installed with the machine room assembly is 1.2×9.8 kg / m 3 , In the step S3, the type and installation position of the lifting lugs are obtained as follows: Step a. First, calculate the weight and center of gravity of each single component one by one, then take the end position of the rear girder as the reference point, and then calculate the center of gravity and weight of the overall lifting component according to the center of gravity and weight of each single component: weight × moment arm = moment; Step b. After obtaining the calculation result of the overall component center of gravity position, offset from the center of gravity position to both sides to find suitable lifting lug installation positions on the rear girder structure; Calculate the force on each lifting lug, that is, the distributed load, according to the distances L1 and L2 from the two-sided lifting lugs to the center of gravity position: F1 + F2 = G, F1 * L1 = F2 * L2, where F1 and F2 are the forces on the lifting lugs and G is the total weight of the component, and then design the structural form of the lifting lugs and select the appropriate type of sling according to the lifting point distributed loads F1 and F2.

2. The overall hoisting method for the rear girder and machine room assembly of the bridge-type ship unloader according to claim 1, characterized in that: The finite element model adopts BEAM44 elements and MASS21 elements.

3. The overall hoisting method of the rear girder and the machine room assembly of the bridge-type ship unloader according to claim 1, characterized in that: Plug-in lifting lugs are adopted on the rear girder assembly.

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