A double-machine four-hoisting-beam lifting system and lifting method

Abstract

The present application relates to a kind of double machine four lifting beam lifting system and hoisting method, including two gantry cranes, two secondary hoisting beams and two main hoisting beams, the vice hook of two cars on the two gantry cranes is hung with one secondary hoisting beam by steel wire rope, two main hoisting beams are parallel and symmetrically arranged, the lower side of the secondary hoisting beam is hung in one main hoisting beam at both ends respectively, another main hoisting beam is hung on the main hook of the lower car of the two gantry cranes, the lifting lug at the lower side of both ends of the two main hoisting beams is connected with the lifting lug arranged on the top plate at both ends of the hoisted object by steel wire rope.The present application can solve the problem that the weight of the hoisted object exceeds the single machine lifting capacity, and the size is smaller than the minimum center distance of the double machine combined lifting two crane beams, and realizes safe hoisting.

Description

Technical Field

[0001] This invention relates to the field of hoisting technology, and in particular to a dual-machine, four-beam lifting system and hoisting method. Background Technology

[0002] The current shipbuilding market is booming, with ship design and construction increasingly trending towards larger, more integrated designs. The goal is to deliver intermediate products in stages to improve construction efficiency. However, existing shipbuilding equipment and facilities are relatively under-configured and cannot meet the industry's evolving needs. In particular, gantry cranes, as the most crucial lifting equipment in shipbuilding, directly impact the overall form and integrity of ship sections. Generally, single-crane or dual-crane lifting is used. For example, an asphalt tank has a total weight of 567.57 tons; a length of 34925 mm, a width of 17100 mm, and a height of 9200 mm. The total weight under the hook (tank body + lifting beam + wire rope weight) is 567.57 + 43*2 + 6.2 + 3.6 + 5*2 = 673.37 tons. A 450-ton gantry crane has the following parameters: span of 66 meters and beam bottom elevation of 60 meters. The main hook has a lifting capacity of 350t + 20t, with two side hooks each holding 175t*2. The side hook span is 10.2m, and the allowable eccentric load on the side hooks is ≤60t. The lifting capacity is 450t. Another 450T gantry crane has the following parameters: span 66m, beam bottom elevation 60m. The main hook has a lifting capacity of 350t + 20t, with two side hooks each holding 175t*2. The side hook span is 11.4m, and the allowable eccentric load on the side hooks is ≤60t. The lifting capacity is 450t.

[0003] When using two gantry cranes for lifting, based on the length of the two rigid legs and a 1m safety distance between the two cranes, the length of the object being lifted must be greater than 19.75m, and the structural strength of the object must meet the requirements. The asphalt tank has a total weight of 567.57T and a length of 34.925m. The maximum lifting capacity of a single gantry crane is 450T. Therefore, for a two-gantry crane lifting operation, the length of the object must be greater than 39.75m. Thus, regardless of whether the asphalt tank is lifted by a single or double crane, this direct lifting method is unsuitable if the weight of the object exceeds the lifting capacity of a single crane, and its dimensions are smaller than the minimum center-to-center distance between the two crane beams used in a double-crane lifting operation. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-machine four-beam lifting system and lifting method that can solve the problem that the weight of the object being lifted exceeds the lifting capacity of a single machine, while its size is smaller than the minimum center distance between the two crane beams in a dual-machine tandem lifting system, thus achieving safe lifting.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a dual-machine four-beam lifting system, characterized in that: it includes two gantry cranes, two secondary lifting beams, and two main lifting beams. Each of the two gantry cranes has a secondary lifting beam suspended from its auxiliary hook via a wire rope. The two main lifting beams are arranged parallel and symmetrically. The lower ends of each secondary lifting beam are respectively attached to both ends of one of the main lifting beams. The other main lifting beam is suspended from the main hook of the two gantry cranes' lower trolleys. The lifting lugs at both ends of the two main lifting beams are connected to lifting lugs on the top plates at both ends of the object being lifted via wire ropes.

[0006] Furthermore, the distance L1 between the upper lifting lugs at both ends of the secondary lifting beam is the same as the span L2 of the corresponding side hook of the gantry crane.

[0007] Furthermore, the distance L3 between the upper lifting lugs at both ends of the main lifting beam is the same as the minimum distance L4 between the centers of the two rigid legs and the two gantry crane beams.

[0008] Furthermore, the lifting lugs on the top plates at both ends of the hoisted object are provided in multiple ways.

[0009] Furthermore, the actual load of a gantry crane shall not exceed 80% of its rated lifting capacity, and the total weight of the lifted object shall not exceed 75% of the sum of the rated lifting capacities of two gantry cranes.

[0010] Furthermore, the two ends below the secondary lifting beam are suspended from the two ends of a main lifting beam by steel wire ropes, and the included angle α1 between the two steel wire ropes suspended above the main lifting beam and the secondary lifting beam is not less than 60°.

[0011] Furthermore, the angle α2 between the steel wire rope hanging below the main lifting beam and the vertical direction does not exceed 4°.

[0012] A lifting method for a dual-machine, four-beam lifting system, the lifting method comprising the following steps: Step S1: Based on the weight of the object being lifted, equip two gantry cranes, two secondary lifting beams, and two main lifting beams, with the two gantry cranes placed in parallel and symmetrical positions; Step S2: A secondary lifting beam is hung on the auxiliary hook of the trolley of each of the two gantry cranes by steel wire rope, converting the hooks on both sides of the trolley into single hooks; Step S3: The two main lifting beams are set parallel and symmetrically. The two secondary lifting beams are respectively attached to the two ends of one main lifting beam by steel wire ropes. The other main lifting beam is attached to the main hook of the two gantry crane trolleys by steel wire ropes.

[0013] Step S4: The lifting lugs at both ends of the two main lifting beams are connected to the lifting lugs on the top plates at both ends of the object being lifted by means of steel wire ropes, and the object is lifted.

[0014] Furthermore, the length of the upper lifting lugs at both ends of the secondary lifting beam is the same as the length of the auxiliary hooks of the gantry crane, and the length of the upper lifting lugs at both ends of the main lifting beam is the same as the minimum distance between the centers of the two gantry crane beams and the length of the two rigid legs.

[0015] The beneficial effects of this invention are as follows: By combining two gantry cranes, two secondary lifting beams, and two main lifting beams, the design solves the problem that the weight of the object being lifted exceeds the lifting capacity of a single crane, while its size is smaller than the minimum center distance between the two crane beams in a dual-crane lifting arrangement. The two secondary lifting beams are arranged symmetrically on the left and right, and the two main lifting beams are stacked parallel to each other front and back, ensuring uniform force distribution during lifting. At the same time, the distributed force distribution through multiple layers of lifting beams and multiple lifting points reduces the risk of single-point failure and improves the overall safety of lifting large objects. Attached Figure Description

[0016] Figure 1 This is a side view of the asphalt tank in this invention; Figure 2 This is a cross-sectional view of the asphalt tank in this invention; Figure 3 This is a top view of the asphalt tank in this invention; Figure 4 This is a schematic diagram of two gantry cranes in this invention; Figure 5 This is a side view of the invention during hoisting; Figure 6 This is a cross-sectional view of the present invention during hoisting; Figure 7 This is a schematic diagram of the main lifting beam of the present invention; Figure 8 This is a schematic diagram of a 10.2m secondary lifting beam in an embodiment of the present invention; Figure 9 This is a schematic diagram of the 11.5m secondary lifting beam in an embodiment of the present invention; Figure 10 This is a schematic diagram showing the center of gravity of the asphalt tank of the present invention; Figure 11 This is a schematic diagram of the cross-sectional lifting point distribution during the hoisting of the present invention. Figure 12 This is a stress cloud diagram for the hoisting of the asphalt tank; Figure 13 This is a cloud map showing the deformation of the asphalt tank during hoisting.

[0017] The components include: 1. Gantry crane, 2. Secondary lifting beam, 3. Main lifting beam, 4. Auxiliary hook, 5. Main hook, and 6. Asphalt tank. Detailed Implementation

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] Please see Figures 1 to 13The present invention provides an embodiment of a dual-machine four-beam lifting system, comprising two gantry cranes 1, two secondary lifting beams 2, and two main lifting beams 3. Each of the two gantry cranes 1 has a secondary lifting beam 2 suspended from its auxiliary hook 4 via a wire rope. The two main lifting beams 3 are arranged parallel and symmetrically. The lower ends of each secondary lifting beam 2 are respectively attached to both ends of one main lifting beam 3. The other main lifting beam 3 is suspended from the main hook 5 of the two gantry cranes 1. The lifting lugs at both ends of the two main lifting beams 3 are connected to the lifting lugs on the top plates at both ends of the object being lifted via wire ropes.

[0020] Please continue reading. Figure 5 , Figure 8 , Figure 9 As shown, in one embodiment of the present invention, the distance L1 between the upper lifting lugs at both ends of the secondary lifting beam 2 is the same as the side hook span L2 of the corresponding gantry crane 1.

[0021] Please continue reading. Figure 4 , Figure 7 As shown, in one embodiment of the present invention, the distance L3 between the upper lifting lugs at both ends of the main lifting beam 3 is the same as the minimum distance L4 between the centers of the two rigid legs of the two gantry crane beams 1.

[0022] Please continue reading. Figure 6 , Figure 11 As shown in one embodiment of the present invention, multiple lifting lugs are provided on the top plates at both ends of the hoisting object.

[0023] Please continue reading. Figures 1 to 11 As shown, in one embodiment of the present invention, the actual load of a gantry crane 1 does not exceed 80% of its rated lifting capacity, and the total weight of the lifted object does not exceed 75% of the sum of the rated lifting capacities of the two gantry cranes 1.

[0024] Please continue reading. Figure 5 As shown, in one embodiment of the present invention, the two ends of the secondary lifting beam 2 are suspended from the two ends of a main lifting beam 3 by steel wire ropes. The angle α1 between the two steel wire ropes suspended above the main lifting beam 3 and the secondary lifting beam is not less than 60°. The angle α1 between the two steel wire ropes should normally not be less than 60 degrees. The length of the steel wire ropes is determined based on the maximum lifting height of the gantry crane 1, the height of the object being lifted, and the maximum lifting height required.

[0025] Please continue reading. Figure 5 As shown, in one embodiment of the present invention, the angle α2 between the steel wire rope hanging below the main lifting beam 3 and the vertical direction does not exceed 4°.

[0026] Please see Figures 1 to 13 The present invention provides another embodiment: a lifting method for a dual-machine four-beam lifting system, the lifting method comprising the following steps: Step S1: Based on the weight of the object being lifted, equip two gantry cranes 1, two secondary lifting beams 2, and two main lifting beams 3, with the two gantry cranes 1 placed in parallel and symmetrical positions; Step S2: A secondary lifting beam 2 is hung on the auxiliary hook 4 of the upper trolley of both gantry cranes 1 by steel wire rope, so as to convert the two hooks on the upper trolley into single hooks. The gantry crane 1 has three hooks, two hooks on the front and rear of the upper and lower trolleys, and one hook on the lower trolley (in the middle). If the two hooks of the upper trolley need to be installed as single hooks, a lifting beam needs to be installed.

[0027] Step S3: The two main lifting beams 3 are set parallel and symmetrically. The two secondary lifting beams 2 are respectively attached to the two ends of one main lifting beam 3 by steel wire ropes. The other main lifting beam 3 is attached to the main hook 5 of the trolley of the two gantry cranes 1 by steel wire ropes.

[0028] Step S4: The lifting lugs at both ends of the two main lifting beams 3 are connected to the lifting lugs on the top plates at both ends of the object being lifted by means of steel wire ropes for lifting.

[0029] Please continue reading. Figure 5 As shown, in one embodiment of the present invention, the distance between the upper lifting lugs at both ends of the secondary lifting beam 2 is the same as the distance between the auxiliary hooks 4 of the gantry crane 1, and the distance between the upper lifting lugs at both ends of the main lifting beam 3 is the same as the minimum distance between the centers of the two rigid legs of the two gantry crane beams 1. Specific Implementation Example 1:

[0030] Taking the asphalt tank 6 mentioned in the background technology above, with a total weight of 567.57T, as an example of the object being lifted: This invention employs a dual-machine, four-beam lifting system, equipped with two 450t gantry cranes (1), two 250t secondary lifting beams (2), and two 400t main lifting beams (3) as mentioned in the background section. It is used for lifting asphalt tanks (6).

[0031] The design incorporates a 400T main lifting beam 3 (self-weight 43T) with a minimum center-to-center distance of 39.75m between the two gantry crane beams. Figure 7 As shown, based on the spacing of the two gantry cranes' hooks 1 and 4, l1:10.2m and l2:11.5m respectively, two secondary lifting beams 2 with a capacity of 250T each (self-weight 3.6T and 6.2T) are designed. Figure 8 and Figure 9 As shown; The asphalt tank 6 is lifted using two gantry cranes 1, each with a secondary lifting beam 2 capable of bearing 250t. The hooks on both sides of the upper trolley are converted into single hooks. The secondary lifting beams 2 are then attached to secondary lifting beams 2 capable of bearing 400t, and to lifting lugs at both ends of the main lifting beam 3. These lugs are connected to the lifting lugs on the top plates at both ends of the asphalt tank 6 via wire rope shackles, allowing for the complete lifting of the asphalt tank 6. Figure 5 , Figure 6 As shown.

[0032] according to Figure 5 , Figure 6 The hook type involves 8 lifting brackets at each end of the asphalt tank 6, such as... Figure 10 , Figure 11 As shown, force calculations are performed: The stern 450T gantry crane has a lever arm d1 of 18035mm, and the bow gantry crane has a lever arm d2 of 16890mm. The total lever arm is 18035 + 16890 = 34925mm. The total weight of the sections is 568T.

[0033] The unit torque is then 568 / 34925; The force on the stern 2# 450T gantry crane 1 is 568 / 34925*16890=275T; The force on the bow 1# 450T gantry crane is 568 / 34925*18035=293T.

[0034] The two main lifting beams are symmetrically arranged and subjected to balanced forces, then: The asphalt tank has a total load capacity of 275T at the stern end and 8 lifting points, with each lifting point bearing a load capacity of 34.4T. The lifting lugs are selected as A40 lifting brackets.

[0035] The asphalt tank has a total load of 293T at the bow end and 8 lifting points, with each lifting point bearing a load of 36.6T. The lifting lugs are A40 lifting brackets.

[0036] The main lifting beam weighs 43 tons (3 beams), the secondary lifting beam weighs 6.2 tons (2 beams), and the total weight of the wire rope shackles is approximately 5 tons. Therefore: The force on the main hook of the 450T gantry crane #2 at the stern is 275 / 2 + 43 / 2 + 5 / 2 = 162T, and the force on the auxiliary hook is 275 / 2 + 43 / 2 + 5 / 2 + 6.2 = 168T. The total force on the hooks is 162 + 168 = 330T, which accounts for 73.3% of the total lifting capacity of the 450T gantry crane #1 (330 / 450 = 73.3%, which is less than 80% of the single machine's lifting capacity).

[0037] The force on the main hook of the 450T gantry crane #1 (under 5 hooks) is 293 / 2 + 43 / 2 + 5 / 2 = 171T, and the force on the auxiliary hook (under 4 hooks) is 293 / 2 + 43 / 2 + 5 / 2 + 3.6 = 174T. The total force under the hooks is 171 + 174 = 345T, which accounts for 76.6% of the total lifting capacity of the 450T gantry crane (345 / 450 = 76.6%) (<80% of the single machine's capacity).

[0038] The total force under the double hooks is 330T + 345T = 675T, which accounts for 75% of the total force of the double hooks (675 / 450*2 = 75%). Both the single-hook force and the percentage of the total force meet the specifications; therefore, double-hook lifting is feasible.

[0039] Asphalt tank 6 body structure strength calculation as follows Figure 12 , Figure 13 As shown, Figure 12The stress values ​​of the tank structure at each lifting point are shown. The darker the color in the figure, the greater the stress value. The calculation results show that the maximum stress is located below the side lifting bracket. The reddest point has the largest stress value, which is 121 MPa. The main structure of asphalt tank 6 is made of DH36 with a yield strength of 355 MPa. The stress has a safety margin of 355 / 121 = 2.9 times. Figure 13 The image shows the deformation of the tank body; the darker the color, the greater the deformation. During hoisting, the deformation is 2.25mm upward at both ends and 1.16mm downward in the middle. The structural strength and deformation both meet the hoisting requirements.

[0040] The present invention has the following working principle: by using two gantry cranes 1, two secondary lifting beams 2 and two main lifting beams 3, it is designed to solve the problem that the weight of the object being lifted exceeds the lifting capacity of a single crane, while the size is smaller than the minimum center distance between the two crane beams in a dual-crane lifting system.

[0041] The above description is only a preferred embodiment of the present invention and should not be construed as a limitation of this application. All equivalent changes and modifications made in accordance with the scope of the patent application of the present invention should be covered by the present invention.

Claims

1. A dual-machine, four-beam lifting system, characterized in that: The system includes two gantry cranes, two secondary lifting beams, and two main lifting beams. Each of the two gantry cranes has a secondary lifting beam suspended from its auxiliary hook via a wire rope. The two main lifting beams are arranged parallel and symmetrically. The lower ends of each secondary lifting beam are respectively attached to the two ends of one of the main lifting beams. The other main lifting beam is attached to the main hook of the two gantry cranes. The lifting lugs at the lower ends of the two main lifting beams are connected to the lifting lugs on the top plates at both ends of the object being lifted via wire ropes.

2. The dual-machine four-beam lifting system according to claim 1, characterized in that: The distance L1 between the upper lifting lugs at both ends of the secondary lifting beam is the same as the span L2 of the corresponding side hook of the gantry crane.

3. The dual-machine four-beam lifting system according to claim 1, characterized in that: The distance L3 between the upper lifting lugs at both ends of the main lifting beam is the same as the minimum distance L4 between the centers of the two rigid legs and the two gantry crane beams.

4. The dual-machine four-beam lifting system according to claim 1, characterized in that: The lifting lugs are provided on the top plates at both ends of the object being lifted.

5. The dual-machine four-beam lifting system according to claim 1, characterized in that: The actual load of a gantry crane shall not exceed 80% of its rated lifting capacity, and the total weight of the lifted object shall not exceed 75% of the sum of the rated lifting capacities of two gantry cranes.

6. The dual-machine four-beam lifting system according to claim 1, characterized in that: The two ends of the secondary lifting beam are suspended from the two ends of the main lifting beam by steel wire ropes, and the included angle α1 between the two steel wire ropes suspended above the main lifting beam and the secondary lifting beam is not less than 60°.

7. The dual-machine four-beam lifting system according to claim 1, characterized in that: The angle α2 between the steel wire rope hanging below the main lifting beam and the vertical direction does not exceed 4°.

8. A lifting method applicable to the dual-machine four-beam lifting system of claim 1, characterized in that: The hoisting method includes the following steps: Step S1: Based on the weight of the object being lifted, equip two gantry cranes, two secondary lifting beams, and two main lifting beams, with the two gantry cranes placed in parallel and symmetrical positions; Step S2: A secondary lifting beam is hung on the auxiliary hook of the trolley of each of the two gantry cranes by steel wire rope, converting the hooks on both sides of the trolley into single hooks; Step S3: The two main lifting beams are set parallel and symmetrically. The two secondary lifting beams are respectively attached to the two ends of one main lifting beam by steel wire ropes. The other main lifting beam is attached to the main hook of the two gantry crane trolleys by steel wire ropes. Step S4: The lifting lugs at both ends of the two main lifting beams are connected to the lifting lugs on the top plates at both ends of the object being lifted by means of steel wire ropes, and the object is lifted.

9. A dual-machine four-beam lifting system according to claim 6, characterized in that: The distance between the upper lifting lugs at both ends of the secondary lifting beam is the same as the distance between the auxiliary hooks of the gantry crane. The distance between the upper lifting lugs at both ends of the main lifting beam is the same as the minimum distance between the centers of the two gantry crane beams and the length of the two rigid legs.

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