A single hook flipping method during welding of large marine diesel engine base

Abstract

The present invention relates to the technical field of diesel engines, and in particular to a single-hook flipping method during the welding process of a diesel engine base for a large ship. The method comprises the following steps: using three-dimensional software modeling to analyze and calculate the center of gravity position of the diesel engine base according to a drawing; determining the distribution position of the flipping lifting lugs according to the calculation result; and ensuring that the angle between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum is less than 2°; using a main hook of a crane to hook the corresponding lifting lug, lifting the main hook of the crane to lift one side of the diesel engine base, and using the contact point between the diesel engine base and the ground as the fulcrum on the other side, and moving the crane in the flipping direction to drive the diesel engine base to flip; the present invention can realize the flipping of the diesel engine base only by using the main hook of the crane, thereby solving the production problem that the coordinated aerial flipping of the double hooks cannot be realized due to insufficient load of the auxiliary hook of the crane, so that most welds in the engine base welding process are in the flat welding position, thereby improving production efficiency and product quality.

Description

Technical Field

[0001] The invention relates to the technical field of diesel engines, in particular to a single hook flipping method during the welding process of a large marine diesel engine base. Background Art

[0002] The engine base of a marine diesel engine is a key component that supports the structural components and moving parts of the diesel engine. It is the "backbone" of the entire diesel engine and must have sufficient rigidity and strength. Therefore, the quality of the engine base welding determines its service life, and the level of production efficiency affects the output benefits of the enterprise.

[0003] During the welding and production process of the marine diesel engine base (weighing approximately 130t or more), the dual-hook coordinated aerial flipping cannot be achieved due to the load limit of the existing crane auxiliary hook (the existing crane main hook load is approximately 150t, and the auxiliary hook load is approximately 35t. If the auxiliary hook is upgraded, the cost is high). If flipping is not performed during the welding process, most of the welds on the marine diesel engine base will be welded in the vertical and horizontal positions, resulting in high labor intensity for workers, low production efficiency, and certain quality risks. Summary of the Invention

[0004] The purpose of the present invention is to provide a single hook flipping method during the welding process of a large marine diesel engine base, so as to solve the problem that the existing crane main hook and auxiliary hook cannot realize the double hook coordinated aerial flipping of the marine diesel engine base. In order to achieve the above object, the present invention solves the problem through the following technical solutions:

[0005] The present invention provides a single hook flipping method during the welding process of a large marine diesel engine base, comprising the following steps:

[0006] According to the drawings, the center of gravity of the diesel engine base is calculated using 3D modeling software. The distribution position of the flipping lifting lugs is determined based on the calculation results, and the angle between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum is ensured to be less than 2°. The corresponding lifting lug is hooked with the main hook of the crane, and the main hook of the crane is lifted to lift one side of the diesel engine base. The other side uses the contact point between the diesel engine base and the ground as the fulcrum, and the crane is moved in the flipping direction to drive the diesel engine base to flip.

[0007] As a further technical solution, the diesel engine base is flipped at an angle of 90° each time, and welding is performed after the main hook of the crane is removed.

[0008] As a further technical solution, lifting ears are arranged on the top of both sides of the diesel engine base, and the lifting ears on both sides are arranged symmetrically.

[0009] As a further technical solution, four lifting ears are provided on each side, the first lifting ear and the fourth lifting ear are provided at both ends, and the second lifting ear and the third lifting ear are provided between the first lifting ear and the fourth lifting ear.

[0010] As a further technical solution, the position of the lifting lug is adjusted by moving it up and down and horizontally to meet the angle requirements between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum.

[0011] As a further technical solution, the first lifting eye and the fourth lifting eye are respectively used in the process of the diesel engine base tipping to different sides, and the second lifting eye and the third lifting eye are respectively used in the process of the diesel engine base standing to different sides.

[0012] As a further technical solution, the lifting lugs should be arranged so that the lifting point is located on the extension line of the line connecting the fulcrum and the center of gravity.

[0013] As a further technical solution, 3D modeling software is used to calculate the structural strength of the hanging points and support points during the flipping process to ensure that the local deformation during the flipping process is less than 1mm.

[0014] As a further technical solution, all product welds should be primed with a layer of welding before the diesel engine base is turned over, and the product welds around the lifting lugs should be filled with more than two layers.

[0015] As a further technical solution, when the diesel engine base hanging point, center of gravity and fulcrum are in a balanced point state on the plumb line, the driving speed is reduced.

[0016] The beneficial effects of the present invention are as follows:

[0017] (1) The present invention first calculates the center of gravity position of the diesel engine base through three-dimensional software, and reasonably arranges the position of the lifting lug based on the position of the center of gravity. The corresponding lifting lug can be hooked with the main hook of the crane. The main hook of the lifting crane is lifted to lift one side of the diesel engine base first, and the other side uses the contact point between the diesel engine base and the ground as a fulcrum. The lifting crane moves in the flipping direction to drive the diesel engine base to flip. This method solves the production problem of being unable to achieve double-hook coordinated aerial flipping during the engine base welding process, ensures welding quality, and improves production efficiency.

[0018] (2) When determining the distribution position of the flipping lifting lugs, the present invention needs to ensure that the angle between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum is less than 2°. When the diesel engine base reaches a balanced state during the flipping process, the diesel engine base can smoothly and stably pass through the balanced state under the cooperation of the main hook of the crane and the diesel engine base, and the diesel engine base avoids or reduces the sudden drag on the main hook of the crane. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which form part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their description are provided to illustrate the present invention and are not intended to limit the present invention. It should also be understood that these drawings are shown for simplicity and clarity and are not necessarily drawn to scale. The present invention will now be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0020] Figure 1 It shows a front view of a diesel engine base in an embodiment of the present invention;

[0021] Figure 2 It shows a side view of a diesel engine base in an embodiment of the present invention;

[0022] Figure 3 A top view of a diesel engine base in an embodiment of the present invention is shown;

[0023] Figure 4 A schematic diagram of the process of rolling over a diesel engine base according to an embodiment of the present invention is shown;

[0024] Figure 5 A schematic diagram of the process of restoring the diesel engine base to its original position after it has flipped over is shown in an embodiment of the present invention;

[0025] Figure 6 It shows a schematic diagram of the diesel engine stand standing process in an embodiment of the present invention;

[0026] Figure 7 A schematic diagram of the process of restoring the diesel engine base to its original posture after standing up is shown in an embodiment of the present invention.

[0027] In the figure: 1, diesel engine base; 11, first lifting eye; 12, second lifting eye; 13, third lifting eye; 14, fourth lifting eye. DETAILED DESCRIPTION

[0028] The technical solutions in typical embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0029] like Figure 1-Figure 7 As shown, this embodiment provides a single hook flipping method during the welding process of a large marine diesel engine base, comprising the following steps:

[0030] According to the drawings, the center of gravity of the diesel engine base 1 is calculated by using 3D modeling software. The distribution position of the flipping lifting lugs is determined based on the calculation results, and the angle between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum is ensured to be less than 2°. The corresponding lifting lug is hooked with the main hook of the crane, and the main hook of the crane is lifted to lift one side of the diesel engine base 1. The other side uses the contact point between the diesel engine base 1 and the ground as the fulcrum, and the crane is moved in the flipping direction to drive the diesel engine base 1 to flip.

[0031] In this embodiment, the center of gravity position of the diesel engine base 1 is first calculated by three-dimensional software, and the position of the lifting lugs is reasonably arranged based on the position of the center of gravity. The diesel engine base can be flipped by simply hooking the corresponding lifting lugs with the main hook of the crane. This method solves the production problem of being unable to achieve coordinated aerial flipping of the double hooks during the base welding process, so that most welds in the base welding process are in the flat welding position, thereby ensuring welding quality and improving production efficiency.

[0032] like Figure 1 、 Figure 2 and Figure 3 As shown, the lifting lugs are arranged symmetrically on the top of both sides of the diesel engine base 1. There are four lifting lugs on each side, with the first lifting lug 11 and the fourth lifting lug 14 being arranged at both ends, and the second lifting lug 12 and the third lifting lug 13 being arranged between the first lifting lug 11 and the fourth lifting lug 14.

[0033] The first lifting eye 11 and the fourth lifting eye 14 are respectively used in the process of the diesel engine base 1 tipping over to different sides, and the second lifting eye 12 and the third lifting eye 13 are respectively used in the process of the diesel engine base 1 standing up to different sides.

[0034] like Figure 4 As shown, it shows the process of the diesel engine base 1 flipping to the right to stand up. At this time, the main hook of the driving crane should be hooked on the fourth lifting lugs 14 on both sides of the diesel engine base 1 (one on each side, a total of two fourth lifting lugs 14). Figure 5 As shown, the diesel engine base 1 is flipped 90 degrees each time, and the welding is performed after the main hook of the driving is removed. After the welding is completed, the main hook of the driving is used to hook the fourth lifting eye 14 to flip the diesel engine base 1 so that the diesel engine base 1 returns to its initial posture.

[0035] Similarly, if Figure 6 As shown, it shows the process of the diesel engine base 1 flipping to the right to achieve the rollover. At this time, the main hook of the driving vehicle should be hooked on the second lifting lug 12 and the third lifting lug 13 on one side of the diesel engine base 1. Figure 7 As shown, the process of restoring the initial posture is shown.

[0036] It is understandable that the diesel engine base 1 can also be tilted to the left or stand upright.

[0037] During the flipping process, a balanced state is achieved after reaching a certain angle. Theoretically, this is the state when the lifting point, center of gravity, and fulcrum are aligned on the same plumb line, and no force is applied to the lifting point. However, due to the structural and dimensional limitations of the diesel engine base, it is difficult to ensure an ideal balanced state. Instead, a non-ideal balanced state may occur, where no force is applied to the lifting lugs. When the balance point is exceeded, a sudden flip at a certain angle may occur, causing a sudden drag on the main hook, increasing instability and potentially causing danger.

[0038] In order to avoid this phenomenon, when determining the distribution position of the flip lugs, it is necessary to ensure that the angle between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum is less than 2°. Figure 1As shown, the angle between the line connecting the lifting point to the fulcrum at the fourth lifting lug 14 and the line connecting the center of gravity and the fulcrum is 0.6°, and the angle between the line connecting the lifting point to the fulcrum at the first lifting lug 11 and the line connecting the center of gravity and the fulcrum is 1.4°, which meets the requirements. When the angle between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum is less than 2°, the balance state can be smoothly and stably passed without sudden drag.

[0039] Ideally, the lifting lugs should be arranged so that the lifting point is located on the extension line of the line connecting the fulcrum and the center of gravity. Figure 2 As shown, the second lifting eye 12 meets the above requirements.

[0040] In order to meet the angle requirements, the position of the lifting lug can be adjusted by moving it up and down or horizontally to meet the angle requirements between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum. Figure 1 As shown, the lifting point height of the first lifting eye 11 is higher than that of the other lifting points, and of course it can be moved to the left to meet the requirements; the fourth lifting eye 14 should be moved to the left as much as possible, and the figure has shown the fourth lifting eye 14 at the extreme position on the left.

[0041] If the angle requirement cannot be met due to structural and size limitations of the diesel engine base 1, the method of this embodiment is not a good choice.

[0042] Use 3D modeling software to calculate the structural strength of the hanging points and support points during the flipping process, check that the workpiece itself does not produce large deformation when the support points are subjected to force, ensure that the local deformation during the flipping process is less than 1mm, and ensure that the dimensions of the steel structure after welding meet the design requirements.

[0043] On-site welding personnel assembled and welded the tilting lugs according to the machine base's contours, center of gravity, and lug layout. The lugs are made of Q235B steel, and welded using CO2 gas shielded welding. The filler metal is AWS 5.18ER70S-6, Ø1.2mm, and the shielding gas is 100% CO2. After a 16-hour cooling period, MT / UT flaw detection was performed according to ISO 5817 Class B standards to verify weld quality.

[0044] Before turning over the diesel engine base 1, all product welds should be primed with a layer of welding, and the product welds within 500mm around the lifting lugs should be filled with two or more layers to ensure the structural strength of the base during the turning process.

[0045] Use 3D software to simulate the main flipping postures during the flipping process, including: the unlifted state, the lifted state but not past the balance point, the balance point state where the lifting point, center of gravity, and fulcrum are on the plumb line, the lifting state after passing the balance point, and the workpiece state after the flip is completed. This can show the flip commander and crane operator the movement process during the flipping process.

[0046] The flip commander and the crane operator execute the flipping work according to the engine base flipping plan. During the flipping process, the commander issues clear operating instructions to the crane operator based on the real-time flipping status, especially when the lifting point, center of gravity and fulcrum of the diesel engine base 1 are in the balance point state on the plumb line, the crane movement speed is reduced, and the movement of the crane main hook and the crane movement must be closely coordinated to avoid causing a crooked and slanted lifting state and thus destroying the balance of the engine base flipping movement.

[0047] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A single hook flipping method during welding of a large marine diesel engine base, characterized in that: The following steps are involved: Use 3D modeling software to analyze and calculate the center of gravity of the diesel engine base based on the drawings. Determine the distribution of the flipping lifting lugs based on the calculation results, and ensure that the angle between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum is greater than 0.6° and less than 2°. Use the main hook of the crane to hook the corresponding lifting lug. Lift the main hook of the crane to lift one side of the diesel engine base. Use the contact point between the diesel engine base and the ground as the fulcrum on the other side. Move the crane in the flipping direction to drive the diesel engine base to flip. There are four lifting eyes on each side. The first and fourth lifting eyes are set at both ends, and the second and third lifting eyes are set between the first and fourth lifting eyes. The position of the lifting eyes can be adjusted by moving up and down and horizontally to meet the angle requirements between the line connecting the lifting point to the fulcrum and the line connecting the center of gravity and the fulcrum; When the diesel engine base lifting point, center of gravity and fulcrum are at the balance point on the plumb line, reduce the moving speed of the vehicle; The diesel engine base is flipped 90 degrees each time, and welding is carried out after removing the main hook of the crane.

2. The single hook flipping method during welding of a large marine diesel engine base according to claim 1, characterized in that: The lifting lugs are set on the top of both sides of the diesel engine base, and the lifting lugs on both sides are arranged symmetrically.

3. The single hook flipping method during welding of a large marine diesel engine base according to claim 1, characterized in that: The first lifting eye and the fourth lifting eye are respectively used in the process of the diesel engine base tipping over to different sides, and the second lifting eye and the third lifting eye are respectively used in the process of the diesel engine base standing up to different sides.

4. The single hook flipping method during welding of a large marine diesel engine base according to claim 1, characterized in that: Use 3D modeling software to calculate the structural strength of the hanging points and support points during the flipping process to ensure that the local deformation during the flipping process is less than 1mm.

5. The single hook flipping method during welding of a large marine diesel engine base according to claim 1, characterized in that: Before turning over the diesel engine base, all product welds should be primed with a layer of welding, and the product welds around the lifting lugs should be filled with more than two layers.

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