Method for hoisting and overturning small-cylinder-diameter low-speed marine diesel engine rack

Abstract

The invention belongs to the technical field of diesel engine rack hoisting, and particularly relates to a small-cylinder-diameter low-speed marine diesel engine rack hoisting and overturning method. Comprising the following steps that firstly, a plurality of walking board bottom plates are welded to side plates of a rack, and the walking board bottom plates are evenly distributed on the two sides of the rack; secondly, the lifting lugs are fixed to the walking board bottom plate in a bolt connection mode; thirdly, the mounting direction of the lifting lugs is selected according to the lifting requirement, wherein the mounting direction comprises vertical mounting or transverse mounting; and fourthly, after lifting and overturning are completed, the lifting lugs are detached, and the walking board bottom plate is reserved for repeated use. According to the invention, modular connection of the lifting lug and the rack is realized. The mounting complexity is obviously reduced, and the requirements of different hoisting scenes are met. And the universality of the hoisting and overturning process is improved. The maintenance cost is reduced. And the replicability and the universality of the process are enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of diesel engine frame hoisting, and particularly relates to a method for hoisting, turning and flipping a frame of a small-bore low-speed marine diesel engine. Background Art

[0002] As the main propulsion power of ocean-going ships, the hoisting of the frame of a low-speed marine diesel engine is crucial during shipbuilding and maintenance. At present, with the continuous development and improvement of hoisting technology, a relatively mature technical system has been formed for the hoisting of the frame of a low-speed marine diesel engine. Professional hoisting teams and advanced hoisting equipment can ensure the safety and efficiency of the frame during hoisting. However, due to the large volume and heavy weight of the frame, and often need to be hoisted in a narrow space.

[0003] In the existing hoisting and turning process of the frame of a small-bore low-speed marine diesel engine, the lifting lugs are generally directly fixed on the side plates of the frame by welding. This method has significant defects: First, welding the lifting lugs requires a large amount of man-hours, and the welding quality directly affects the hoisting safety; Second, after the frame is transported to the general assembly workshop, it is no longer necessary to turn it over. Due to interference between the upper lifting lugs and pipelines or other components, secondary cutting is required. The cutting process is not only inefficient, but also damages the paint on the surface of the frame, increasing the painting cost. In addition, the welded lifting lugs are disposable structures and cannot be reused, resulting in waste of resources. These problems seriously restrict production efficiency and cost control. Summary of the Invention

[0004] In order to solve the problems in the existing hoisting and turning of the frame of a small-bore low-speed marine diesel engine, such as consuming a large amount of man-hours, the welding quality directly affecting the hoisting safety, the need for secondary cutting after hoisting and turning, low efficiency, damaging the paint on the surface of the frame, increasing the painting cost, the welded lifting lugs being disposable structures and unable to be reused, resulting in waste of resources, etc., the present invention proposes a method for hoisting, turning and flipping a frame of a small-bore low-speed marine diesel engine, including the following steps: S1: Weld a plurality of platform bottom plates on the side plates of the frame, and the platform bottom plates are evenly distributed on both sides of the frame;

[0005] S2: Fix the lifting lugs to the platform bottom plates by bolt connection;

[0006] S3: Select the installation direction of the lifting lugs according to the hoisting requirements, including vertical installation or horizontal installation;

[0007] S4: Remove the lifting lugs after completing the hoisting and turning, and keep the platform bottom plates for reuse.

[0008] According to the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine described above, the platform bottom plate is rectangular, and threaded holes for the platform bottom plate are reserved thereon, and the threaded holes for the platform bottom plate are symmetrically distributed; the lifting lug includes a lifting lug bottom plate that is threadedly connected to the platform bottom plate, and a first reinforcing rib and a second reinforcing rib are respectively fixedly connected to both ends of the upper surface of the lifting lug bottom plate; a lifting lug main board is also fixedly connected to the upper surface of the lifting lug bottom plate, and both side surfaces of the lifting lug main board are fixedly connected to the first reinforcing rib and the second reinforcing rib respectively; a lifting lug hole for installing a lifting rope is provided on the lifting lug main board.

[0009] According to the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine described above, the number of the platform bottom plates arranged on one side of the frame is 8, including a first platform bottom plate, a second platform bottom plate, a third platform bottom plate, a fourth platform bottom plate, a fifth platform bottom plate, a sixth platform bottom plate, a seventh platform bottom plate, and an eighth platform bottom plate; a total of 16 platform bottom plates are arranged on both sides of the frame; the long sides of the first platform bottom plate, the second platform bottom plate, the third platform bottom plate, and the fourth platform bottom plate are horizontally arranged; the first platform bottom plate and the second platform bottom plate are arranged on the upper part of one side of the frame, and the distances from their vertical centerlines to both sides of one side of the frame are 1 / 4 to 1 / 5 of the horizontal side length of one side of the frame, and the third platform bottom plate and the fourth platform bottom plate are symmetrically arranged with the first platform bottom plate and the second platform bottom plate respectively on the lower part of one side of the frame; the long sides of the fifth platform bottom plate, the sixth platform bottom plate, the seventh platform bottom plate, and the eighth platform bottom plate are vertically arranged; the fifth platform bottom plate and the sixth platform bottom plate are respectively arranged below the first platform bottom plate and the second platform bottom plate; the seventh platform bottom plate and the eighth platform bottom plate are symmetrically arranged with the fifth platform bottom plate and the sixth platform bottom plate respectively on the lower part of one side of the frame and above the third platform bottom plate and the fourth platform bottom plate.

[0010] According to the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine described above, the lifting lug is made of high-strength alloy steel, and the bolt hole positions thereof match the reserved hole positions of the platform bottom plate.

[0011] According to the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine described above, the installation direction of the lifting lug is realized by replacing the platform bottom plates in different directions. When the long side of the lifting lug main board is horizontally arranged, the lifting lug main boards are all installed on the platform bottom plates arranged in the horizontal direction.

[0012] According to the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine described above, the bolt connection adopts a combination of a locknut and a gasket to ensure the connection stability during the hoisting process.

[0013] According to the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine described above, the surface of the platform bottom plate is subjected to anti-rust treatment, and a high-temperature resistant protective layer is coated at the welding joint with the side plate of the frame.

[0014] According to the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine described above, after the lifting lugs are removed, the platform floor plate remains on the frame for the installation of other subsequent auxiliary components.

[0015] According to the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine described above, the method is applicable to the frame of a low-speed marine diesel engine with a cylinder diameter less than 200 mm.

[0016] According to the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine described above, the installation direction of the lifting lugs is adjusted by rotating the platform floor plate or replacing the platform floor plate with prefabricated holes at different angles.

[0017] The beneficial effects of the present invention are described as follows:

[0018] 1. In the hoisting and flipping process of the present invention, by welding the platform floor plate as an intermediate connecting piece to replace directly welding the lifting lugs, modular connection between the lifting lugs and the frame is achieved.

[0019] 2. The present invention uses bolt connection to replace welding, significantly reducing the installation complexity, and the lifting lugs can be quickly disassembled and reused, thus optimizing the hoisting and flipping process.

[0020] 3. By adjusting the installation direction of the platform floor plate, the present invention supports the horizontal or vertical installation of the lifting lugs to meet the requirements of different hoisting scenarios, improving the versatility of the hoisting and flipping process.

[0021] 4. The present invention does not require secondary removal of the lifting lugs, avoiding damage to the paint on the frame surface and reducing the maintenance cost.

[0022] 5. The present invention has a standardized design: the positioning, clamping, and flipping process is standardized, enhancing the replicability and versatility of the process. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of welding the platform floor plate on the side plate of the frame of the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine of the present invention.

[0024] Figure 2 It is a schematic diagram of the structure of the lifting lugs of the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine of the present invention.

[0025] Figure 3 It is a schematic diagram of installing the lifting lugs in the form of bolt connection in the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine of the present invention.

[0026] Figure 4 It is a schematic diagram of changing the installation direction of the lifting lugs by replacing the floor plate in the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine of the present invention.

[0027] In the figure: 1 - catwalk bottom plate, 2 - lifting lug, 11 - first catwalk bottom plate, 12 - second catwalk bottom plate, 13 - third catwalk bottom plate, 14 - fourth catwalk bottom plate, 15 - fifth catwalk bottom plate, 16 - sixth catwalk bottom plate, 17 - seventh catwalk bottom plate, 18 - eighth catwalk bottom plate, 20 - lifting lug bottom plate, 21 - first reinforcing rib, 22 - second reinforcing rib, 23 - lifting lug main board, 24 - lifting lug hole. Detailed implementation mode

[0028] Preferred implementation mode

[0029] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0030] As Figures 1 to 4 shown: In this embodiment, the method for hoisting and flipping the frame of a small-bore low-speed marine diesel engine includes the following steps:

[0031] S1: Weld a number of catwalk bottom plates 1 on the side plates of the frame, and the catwalk bottom plates 1 are evenly distributed on both sides of the frame;

[0032] S2: Fix the lifting lug 2 on the catwalk bottom plate 1 by means of bolt connection;

[0033] S3: Select the installation direction of the lifting lug 2 according to the hoisting requirements, including vertical installation or horizontal installation;

[0034] S4: Remove the lifting lug 2 after completing the hoisting and flipping, and keep the catwalk bottom plate 1 for repeated use.

[0035] The catwalk bottom plate 1 is rectangular, and threaded holes for the catwalk bottom plate are reserved thereon, and the threaded holes for the catwalk bottom plate are symmetrically distributed; the lifting lug 2 includes a lifting lug bottom plate 20 that is threadedly connected with the catwalk bottom plate 1. At both ends of the upper surface of the lifting lug bottom plate 20, a first reinforcing rib 21 and a second reinforcing rib 22 are respectively fixedly connected; a lifting lug main board 23 is also fixedly connected to the upper surface of the lifting lug bottom plate 20, and both side surfaces of the lifting lug main board 23 are fixedly connected with the first reinforcing rib 21 and the second reinforcing rib 22; a lifting lug hole 24 for installing a lifting rope is provided on the lifting lug main board 23.

[0036] There are 8 platform bottom plates 1 arranged on one side of the frame, including the first platform bottom plate 11, the second platform bottom plate 12, the third platform bottom plate 13, the fourth platform bottom plate 14, the fifth platform bottom plate 15, the sixth platform bottom plate 16, the seventh platform bottom plate 17, and the eighth platform bottom plate 18; a total of 16 platform bottom plates 1 are arranged on both sides of the frame; the long sides of the first platform bottom plate 11, the second platform bottom plate 12, the third platform bottom plate 13, and the fourth platform bottom plate 14 are horizontally arranged; the first platform bottom plate 11 and the second platform bottom plate 12 are arranged at the upper part of one side of the frame, and the distances from their vertical centerlines to both sides of one side of the frame are 1 / 4 to 1 / 5 of the horizontal side length of one side of the frame. The third platform bottom plate 13 and the fourth platform bottom plate 14 are symmetrically arranged with the first platform bottom plate 11 and the second platform bottom plate 12 at the lower part of one side of the frame respectively; the long sides of the fifth platform bottom plate 15, the sixth platform bottom plate 16, the seventh platform bottom plate 17, and the eighth platform bottom plate 18 are vertically arranged; the fifth platform bottom plate 15 and the sixth platform bottom plate 16 are arranged below the first platform bottom plate 11 and the second platform bottom plate 12 respectively; the seventh platform bottom plate 17 and the eighth platform bottom plate 18 are symmetrically arranged with the fifth platform bottom plate 15 and the sixth platform bottom plate 16 respectively at the lower part of one side of the frame, above the third platform bottom plate 13 and the fourth platform bottom plate 14.

[0037] The lifting lugs 2 are made of high-strength alloy steel, and the bolt hole positions thereof match the reserved hole positions of the platform bottom plate 1.

[0038] The installation direction of the lifting lug 2 is realized by replacing the platform bottom plate 1 in different directions. When the long side of the lifting lug main board 23 is horizontally arranged, the lifting lug main board 23 is installed on the platform bottom plate 1 arranged in the horizontal direction.

[0039] The bolt connection adopts a combination of a locknut and a gasket to ensure the connection stability during the lifting process.

[0040] The surface of the platform bottom plate 1 is treated with rust prevention, and a high-temperature resistant protective layer is coated at the welding joint with the side plate of the frame.

[0041] After the lifting lug 2 is disassembled, the platform bottom plate 1 remains on the frame for the installation of other subsequent auxiliary components. The method of the present invention is applicable to the frame of a low-speed marine diesel engine with a cylinder diameter less than 200 mm.

[0042] The adjustment of the installation direction of the lifting lug 2 is realized by rotating the platform bottom plate 1 or replacing the platform bottom plate 1 with prefabricated hole positions at different angles.

[0043] In this embodiment, the method for lifting and flipping the frame of a small-bore low-speed marine diesel engine includes the following steps:

[0044] Step 1: Weld the platform bottom plate 1.

[0045] According to the frame structure design drawing, determine the welding position of the platform bottom plate 1. Eight platform bottom plates 1 are evenly arranged on both sides of the frame, with a total of 16 on both sides to ensure symmetrical distribution.

[0046] The platform bottom plate 1 is welded to the designated position of the frame side plate by using carbon dioxide gas shielded welding. Before welding, the welding area needs to be cleaned to remove oil stains and oxide layers.

[0047] The surface of the platform bottom plate 1 is coated with epoxy anti-rust paint after sandblasting, and the welding parts are additionally coated with high-temperature resistant silicone sealant to prevent rust in the welding heat-affected zone.

[0048] Step 2: Install the lifting lug 2.

[0049] The lifting lug 2 is forged from high-strength alloy steel, and a lifting lug bolt hole matching the platform bottom plate 1 is provided at the bottom thereof.

[0050] Use high-strength hexagonal bolts: specification M20×50, pass through the ear holes and the reserved holes on the walkway bottom plate, and fasten with anti-loosening nuts and spring washers.

[0051] If vertical installation is required, fix the lifting lug 2 vertically on the platform base plate 1; if horizontal installation is required, select a platform base plate 1 with horizontal holes, or adjust the hole direction by rotating the base plate 1 and then install the lifting lug 2.

[0052] Step 3: Lifting and flipping operation

[0053] Before lifting, check the torque value of all bolt connections. The standard torque is 180N·m to ensure that there is no looseness.

[0054] Use a crane or gantry crane with a sling to hook the lifting lug 2 and complete the rack flip according to the process requirements. During the flipping process, the center of gravity of the rack must be monitored to avoid tilting.

[0055] Step 4: Disassembly and reuse

[0056] After the lifting is completed, use a pneumatic wrench to remove the bolts and take off the lifting lug 2.

[0057] The walkway bottom plate 1 is retained on the frame, and its surface is not damaged, and can be directly used for subsequent hoisting or other accessories, such as the installation of a sensor bracket.

[0058] Example Description

[0059] Take the low-speed marine diesel engine frame with a cylinder diameter of 180mm as an example:

[0060] 16 walkway bottom plates 1 are welded on both sides of the frame, 8 on one side, and the size of the walkway bottom plate 1 is 150mm×100mm×12mm, with a spacing of 500mm.

[0061] The lifting lug 2 is selected to adopt a horizontal installation mode to adapt to the lifting space in a narrow workshop. By replacing the platform floor plate 1 with horizontal openings, the direction adjustment can be quickly completed.

[0062] After lifting, the lifting lug 2 is disassembled, and the platform floor plate 1 is retained for subsequent installation and debugging of the temporary support, realizing multi-functional reuse.

[0063] In this embodiment, the installation efficiency of the lifting lug 2 is increased by 40%, and there is no need for welding and subsequent cutting processes.

[0064] The reuse rate of the lifting lug 2 and the platform floor plate 1 reaches 100%, and the material cost of each single rack is saved by about 1200 yuan.

[0065] The intact rate of the paint on the surface of the rack is increased from 60% of the traditional process to 98%, and the painting repair working hours are reduced by about 15 hours per unit.

[0066] The above embodiments in combination with the attached Figures 1 to 4 detail the operation details of each step and fully verify the feasibility and superiority of the present invention.

[0067] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A method for hoisting and turning over a frame of a small-bore, low-speed marine diesel engine, characterized in that: The following steps are involved: S1: welding a plurality of platform bottom plates (1) on the side plates of the frame, wherein the platform bottom plates (1) are evenly distributed on both sides of the frame; S2: Fixing the lifting lug (2) to the platform bottom plate (1) by bolt connection; S3: Select the installation direction of the lifting lug (2) according to lifting requirements, including vertical installation or horizontal installation; S4: After the lifting and flipping are completed, the lifting lug (2) is removed and the platform bottom plate (1) is retained for reuse.

2. The method for lifting and turning over a frame of a small-bore, low-speed marine diesel engine according to claim 1, characterized in that: The platform base plate (1) is rectangular, and is provided with platform base plate threaded holes, which are symmetrically distributed; the lifting lug (2) comprises a lifting lug base plate (20) threadedly connected to the platform base plate (1), and the first reinforcing rib (21) and the second reinforcing rib (22) are respectively fixedly connected at both ends of the upper surface of the lifting lug base plate (20); the upper surface of the lifting lug base plate (20) is also fixedly connected to a lifting lug main plate (23), and the two side surfaces of the lifting lug main plate (23) are respectively fixedly connected to the first reinforcing rib (21) and the second reinforcing rib (22); the lifting lug main plate (23) is provided with a lifting lug hole (24) for installing a lifting rope.

3. The method for lifting and turning over a frame of a small-bore, low-speed marine diesel engine according to claim 2, characterized in that: The number of walkway bottom plates (1) arranged on one side of the frame is 8, including a first walkway bottom plate (11), a second walkway bottom plate (12), a third walkway bottom plate (13), a fourth walkway bottom plate (14), a fifth walkway bottom plate (15), a sixth walkway bottom plate (16), a seventh walkway bottom plate (17), and an eighth walkway bottom plate (18); a total of 16 walkway bottom plates (1) are arranged on both sides of the frame; the long sides of the first walkway bottom plate (11), the second walkway bottom plate (12), the third walkway bottom plate (13), and the fourth walkway bottom plate (14) are arranged horizontally; the first walkway bottom plate (11) and the second walkway bottom plate (12) are arranged on the upper part of one side of the frame, and the distances from their vertical center lines to the two sides of one side of the frame are 1 / 4 to 1 / 4 of the horizontal side length of the one side of the frame. 1 / 5, the third walkway bottom plate (13) and the fourth walkway bottom plate (14) are symmetrically arranged at the lower part of one side of the frame with the first walkway bottom plate (11) and the second walkway bottom plate (12) respectively; the fifth walkway bottom plate (15), the sixth walkway bottom plate (16), the seventh walkway bottom plate (17) and the eighth walkway bottom plate (18) are arranged vertically with their long sides; the fifth walkway bottom plate (15) and the sixth walkway bottom plate (16) are arranged below the first walkway bottom plate (11) and the second walkway bottom plate (12) respectively; the seventh walkway bottom plate (17) and the eighth walkway bottom plate (18) are symmetrically arranged at the lower part of one side of the frame with the fifth walkway bottom plate (15) and the sixth walkway bottom plate (16) respectively, and above the third walkway bottom plate (13) and the fourth walkway bottom plate (14).

4. The method for lifting and turning over a frame of a small-bore, low-speed marine diesel engine according to claim 3 is characterized in that: The lifting lug (2) is made of high-strength alloy steel, and the bolt hole position of the lifting lug (2) matches the reserved hole position of the platform bottom plate (1).

5. The method for lifting and turning over a frame of a small-bore, low-speed marine diesel engine according to claim 4 is characterized in that: The installation direction of the lifting lug (2) is achieved by replacing the platform bottom plate (1) in different directions. When the long side of the lifting lug main plate (23) is arranged in the horizontal direction, the lifting lug main plate (23) is installed on the platform bottom plate (1) arranged in the horizontal direction.

6. The method for lifting and turning over a frame of a small-bore, low-speed marine diesel engine according to claim 5, characterized in that: The bolt connection adopts a combination of anti-loosening nuts and washers to ensure the connection stability during the lifting process.

7. The method for lifting and turning over a frame of a small-bore, low-speed marine diesel engine according to claim 6, characterized in that: The surface of the platform bottom plate (1) is treated to prevent rust, and a high temperature resistant protective layer is coated at the welding point with the frame side plate.

8. The method for lifting and turning over a frame of a small-bore, low-speed marine diesel engine according to claim 7, characterized in that: After the lifting lugs (2) are removed, the platform bottom plate (1) remains on the frame for subsequent installation of other auxiliary components.

9. The method for lifting and turning over a frame of a small-bore, low-speed marine diesel engine according to claim 8, characterized in that: The method is applicable to a low-speed marine diesel engine frame with a cylinder diameter less than 200 mm.

10. The method for lifting and turning over a frame of a small-bore, low-speed marine diesel engine according to claim 9, characterized in that: The installation direction of the lifting lug (2) is adjusted by rotating the platform bottom plate (1) or replacing the platform bottom plate (1) prefabricated with holes at different angles.

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