A special lifting and turning-over tool for a marine diesel engine connecting rod

Abstract

A special lifting and turning fixture for marine diesel engine connecting rods. It utilizes the threaded holes on the connecting rod to achieve lifting and turning. The fixture consists of a plate welded to four fixed-pole tubes, with the base plate corresponding to the threaded holes on the connecting rod. A rotating eye bolt is used at the thin end of the connecting rod, while a special fixture combined with a rotating eye bolt is used at the thick end, achieving the purpose of lifting and turning. This fixture ensures the safety, convenience, and practicality of lifting and turning the connecting rod during processing.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical processing technology, specifically relating to a special lifting and turning fixture for marine diesel engine connecting rods, used to achieve safe lifting, turning and transport of connecting rods during processing, and applicable to multi-station processing scenarios of marine diesel engine connecting rods. Background Technology

[0002] As a key moving component of a marine diesel engine, the connecting rod plays a crucial role in converting the reciprocating motion of the piston into the rotational motion of the crankshaft. Its machining quality directly affects the engine's reliability, durability, and power performance. During manufacturing, the connecting rod undergoes multiple processes including milling, drilling, boring, and grinding. Due to its complex structure (typically divided into thin and thick ends), frequent lifting, turning, and relocation are required during processing to meet the clamping and machining requirements of different machine tools.

[0003] Currently, the lifting and turning of marine diesel engine connecting rods mainly rely on the following methods, but all of them have significant limitations:

[0004] Wire rope or chain hoisting method: uneven force can easily lead to deformation of the connecting rod, affecting processing accuracy; manual adjustment is required when turning over, which poses a safety hazard; frequent friction may damage the surface of the connecting rod, affecting subsequent heat treatment or assembly quality.

[0005] General lifting tools (such as magnetic chucks or mechanical grippers) are difficult to adapt to the size and center of gravity differences of different models of connecting rods, and are prone to tilting or slippage; they cannot achieve stable turning, require additional tooling assistance, and reduce production efficiency.

[0006] Simple bolt fixing fixtures can only achieve unidirectional lifting, and need to be disassembled and reassembled when turning over, which is cumbersome; insufficient rigidity may cause vibration and affect the quality of the machined surface.

[0007] To address the aforementioned issues, a specialized lifting and turning fixture is urgently needed. This fixture should ensure stable stress distribution through a rigid welded structure, achieve multi-angle adjustment using rotating eye bolts, and enhance adaptability through positioning via connecting rod bolt holes. This fixture can significantly improve processing efficiency and safety, meeting the high standards required for modern marine diesel engine manufacturing. Utility Model Content

[0008] This utility model provides a special lifting and turning fixture for marine diesel engine connecting rods, aiming to solve the problems of low safety, insufficient efficiency, and poor adaptability of existing lifting methods. Through optimized structural design, it achieves safe lifting, stable turning, and efficient transfer of the connecting rod during processing, ensuring processing accuracy and improving production efficiency.

[0009] The technical solution of this utility model is as follows:

[0010] A special lifting and turning fixture for marine diesel engine connecting rods, characterized in that it includes:

[0011] The base plate is made of high-strength steel plate and has through holes that match the mounting screw holes of the connecting rod for fixing and connecting with bolts;

[0012] A fixed-rectangle tube frame is welded to the base plate to form a rigid support structure;

[0013] The rotating eye bolt is installed at the thin end of the base plate to connect to lifting equipment and enable multi-angle adjustment.

[0014] The adapter block is located at the thick end of the base plate and is used in conjunction with the rotating eye screw to enhance the load-bearing stability of the thick end.

[0015] Furthermore, the layout of the through holes in the base plate can be adjusted according to the screw hole positions of different models of connecting rods to achieve modular adaptation.

[0016] Furthermore, the fixed-rectangle tube frame is a rectangular or trapezoidal welded structure with a tube wall thickness of not less than 5mm to ensure overall bending stiffness.

[0017] Furthermore, the rated load of the rotating eye bolt is not less than 1.5 times the weight of the connecting rod, and it can rotate 360° to meet the angle adjustment requirements when turning over.

[0018] Furthermore, the adapter block is detachable and is connected to the base plate by high-strength bolts to accommodate structural differences in the thickness of different connecting rods.

[0019] Furthermore, the total weight of the tooling should not exceed 10% of the weight of the connecting rod, in order to avoid additional loads affecting the lifting balance.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] High-strength steel plates are used, precisely matching the mounting screw holes of the connecting rod to ensure accurate positioning. The existing mounting screw holes on the connecting rod are used for fixing, avoiding additional machining and ensuring strong adaptability.

[0022] The thin end of the connecting rod uses a rotating eye bolt, while the thick end uses a special tooling with a rotating eye bolt to achieve the purpose of lifting and turning.

[0023] Ensure the safety, convenience, and practicality of lifting and turning the connecting rod during processing. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the connecting rod of a WINGD marine low-speed diesel engine, where 11 is the installation position of the rotating eye bolt and 12 is the installation position of the special tooling.

[0025] Figure 2This is a side view of the special lifting and turning fixture for marine diesel engine connecting rods according to this utility model;

[0026] Figure 3 This is a top view of the special lifting and turning fixture for marine diesel engine connecting rods according to this utility model. Detailed Implementation

[0027] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. This embodiment takes the lifting and turning of the connecting rod of a WINGD marine low-speed diesel engine as an example, but the scope of protection of the present invention is not limited to this model.

[0028] like Figure 1 and Figure 2 As shown, the special lifting and turning fixture for marine diesel engine connecting rods in this embodiment mainly consists of the following components:

[0029] Base plate 1 is made of Q345B high-strength alloy steel plate, with dimensions of 600mm × 400mm × 25mm. After CNC milling, four Φ22mm positioning holes are precisely machined on its upper surface, with hole position tolerance controlled within ±0.03mm. Each positioning hole is tapped with M20×2.5 high-strength threads, with a thread depth of 35mm. An annular weight-reducing groove is machined on the lower surface of the base plate to keep the weight below 45kg while ensuring strength.

[0030] The fixed-rectangle tube frame 2, welded to the base plate 1, consists of two 80mm×80mm×8mm square steel tube columns and one 100mm×50mm×6mm rectangular steel tube beam. CO2 gas shielded welding is used, with spot welding for positioning followed by continuous welding. All welds undergo 100% ultrasonic testing to ensure welding quality. The overall frame height is 350mm, forming a stable portal frame structure with the base plate.

[0031] The swivel eye bolt, grade G80, with M24×3 thread, rated load 5 tons, is installed on the thin end adapter of base plate 1. It is used to connect lifting equipment and achieve multi-angle adjustment. Apply thread-locking adhesive during installation and tighten with a torque wrench to a torque of 300 N·m.

[0032] Adapter block 4 is made of ZG270-500 cast steel, machined after normalizing. It is welded to the thick end of base plate 1 and used in conjunction with the rotating eye bolt to enhance the load-bearing stability of the thick end. The upper platform is machined with M24mm eye mounting holes.

[0033] Tooling usage method

[0034] (1) Installation preparation

[0035] ① Clean the mounting surface and threaded holes of the connecting rod to remove burrs and oil stains;

[0036] ②Inspect the integrity of each hoisting component to confirm that there are no cracks, deformations or other defects;

[0037] ③ Prepare 8.8 grade M20×80 high-strength bolts and matching anti-loosening washers.

[0038] (2) Tooling installation

[0039] ① Place the base plate 1 stably on the connecting rod 5, aligning all the positioning holes;

[0040] ② Install the bolts in diagonal order, and tighten them in three stages to a final torque of 450 N·m;

[0041] ③ Use a precision level with a diameter of 0.02 mm / m to check the flatness of the installation surface and ensure that the gap is ≤0.08 mm.

[0042] (3) Lifting operation

[0043] ① A 10-ton bridge crane is selected, and the hook is equipped with an electronic weighing system;

[0044] ② Connect the main hook to the rotating eye bolt, and connect the auxiliary hook to the load-bearing eye;

[0045] ③ Slowly lift it to 100mm off the ground, observe it for 2 minutes, and continue lifting after confirming that there are no abnormalities.

[0046] (4) Rolling over control

[0047] ① When a 180° turn is required, first lift the two suspension points simultaneously at a speed of 0.8 m / min;

[0048] ②After the connecting rod is 1m off the ground, reduce the speed of the auxiliary hook so that the connecting rod flips at an angular velocity of about 0.7° / s;

[0049] ③ Pause when flipping to 90° and check the condition of each connection part;

[0050] ④ After confirming that everything is correct, continue to rotate to 180°, keep it stable, and then slowly lower it.

[0051] This embodiment demonstrates the best implementation of the present invention, but those skilled in the art can make appropriate modifications without departing from the concept of the present invention, and all such modifications should be covered within the protection scope of the present invention.

Claims

1. A lifting and turning tool for a marine diesel engine connecting rod, characterized in that, include: The base plate (1) is made of high-strength steel plate and has through holes that match the mounting screw holes of the connecting rod for fixing and connecting by bolts; A fixed-rectangle tube frame (2) is welded to the base plate (1) to form a rigid support structure; The rotating eye bolt is installed at the thin end adapter position of the base plate (1) to connect the lifting equipment and realize multi-angle adjustment; The adapter block (4) is located at the thick end of the base plate (1) and is used in conjunction with the rotating eye screw to enhance the load-bearing stability of the thick end.

2. The lifting and turning device according to claim 1, characterized in that: The layout of the through holes in the base plate (1) can be adjusted according to the screw hole positions of different models of connecting rods to achieve modular adaptation.

3. The lifting and turning device according to claim 1, characterized in that: The fixed-rectangular tube frame (2) is a rectangular or trapezoidal welded structure with a tube wall thickness of not less than 5mm to ensure overall bending stiffness.

4. The lifting and turning device according to claim 1, characterized in that: The rated load of the rotating eye bolt is not less than 1.5 times the weight of the connecting rod, and it can rotate 360° to meet the angle adjustment requirements when turning over.

5. The lifting and turning device according to claim 1, characterized in that: The special adapter block (4) is designed to be detachable and is connected to the base plate (1) by high-strength bolts to accommodate the structural differences of different connecting rod thicknesses.

6. The lifting and turning fixture according to any one of claims 1-5, characterized in that: The total weight of the tooling should not exceed 10% of the weight of the connecting rod, so as to avoid additional load affecting the lifting balance.

Images