High-precision positioning method for crankshaft and shafting of marine low-speed high-power diesel engine

Abstract

The invention relates to a high-precision positioning method for a crankshaft and a shafting of a marine low-speed high-power diesel engine, which comprises the following steps of: S1, prefabricating a high-precision drill plate, and respectively printing CS and IS marks on two side surfaces of the drill plate; s2, the CS face of the high-precision drill plate and the diesel engine crankshaft connecting flange are accurately positioned, and a connecting hole finished product is directly machined; s3, the IS face of the high-precision drill plate and the shaft system connecting flange are accurately positioned, and a connecting hole finished product is directly machined; and S4, when the ship is installed, the crankshaft connecting flange and the shaft system connecting flange of the diesel engine are aligned, and finished product assembling is completed. The high-precision alignment requirement of the crankshaft and the shaft system of the marine low-speed high-power diesel engine can be effectively met, the drilling and reaming procedure after flange connecting hole connection at present can be omitted, and therefore the assembling performance and the assembling efficiency are improved, and meanwhile the machining cost can be effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of diesel engine crankshaft precision manufacturing, and in particular to a method for high-precision positioning of a crankshaft and a shaft system of a marine low-speed high-power diesel engine. Background Art

[0002] The crankshaft weight of a low-speed, high-power marine diesel engine is generally between 45 tons and 539 tons, and the total length is between 7 meters and 23 meters. After the crankshaft is manufactured, it is assembled on the diesel engine. After the diesel engine is assembled and tested, it is assembled with the ship during ship construction. The crankshaft output end is aligned and connected with the marine shaft system with high precision. When the ship is running, the propeller at the tail of the shaft system provides power for navigation.

[0003] Since the output end of the crankshaft must be connected with the marine crankshaft with high precision, the crankshaft and shaft system manufacturers usually pre-process the connection holes at the connection parts, and then align the flanges of the two when assembling them on the ship, and then drill and ream the front and rear end alignment connection holes to ensure the connection accuracy. Although this can ensure the connection accuracy to a certain extent, it will also consume a lot of time and manpower and material resources when assembling the diesel engine on the ship. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a method for high-precision positioning of the crankshaft and shaft system of a low-speed, high-power marine diesel engine, which can effectively solve the problems of low operating efficiency and high cost in the crankshaft and shaft system assembly process of the existing methods.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A method for high-precision positioning of a crankshaft and a shaft system of a low-speed, high-power marine diesel engine proposed in the present invention comprises the following steps:

[0007] S1, prefabricated high-precision drilling template, with CS and IS marks printed on both sides of the drilling template;

[0008] S2. Precisely position the CS surface of the high-precision drilling template and the diesel engine crankshaft connection flange, and directly process the connection hole product;

[0009] S3. Precisely position the IS surface of the high-precision drilling template and the shaft connection flange, and directly process the connection hole product;

[0010] S4. During installation on board a ship, align the diesel engine crankshaft connection flange with the shaft connection flange to complete the finished product assembly.

[0011] Furthermore, in step S1, positioning stoppers are provided on both sides of the high-precision drilling template, and the stoppers have the same axiality; the surface of the high-precision drilling template is designed with evenly distributed connecting holes, which serve as reference holes for machining and aligning the connecting holes of the crankshaft and the shaft system.

[0012] Furthermore, the high-precision drilling template is made of anti-deformation material.

[0013] Furthermore, in step S2, after the diesel engine crankshaft connecting flange is processed into a finished product in the previous process, the diesel engine crankshaft connecting flange surface is used as a reference for leveling; the high-precision drilling template CS surface and the diesel engine crankshaft connecting flange are aligned with high precision, and then fixed to ensure that each connecting hole of the high-precision drilling template is aligned with the corresponding connecting hole of the diesel engine crankshaft; the diesel engine crankshaft connecting flange alignment holes are processed based on the connecting holes of the high-precision drilling template, and the processing ensures concentricity and the dimensional tolerance is guaranteed to be within 0~+0.01mm.

[0014] Furthermore, in step S3, the shaft connection flange is processed as a finished product in the previous process, and the shaft connection flange surface is used as a reference for leveling; the IS surface of the high-precision drilling template and the shaft connection flange are aligned with high precision, and then fixed to ensure that each connection hole of the high-precision drilling template is aligned with the corresponding connection hole of the shaft system; the shaft connection flange alignment holes are processed based on the connection holes of the high-precision drilling template, and the processing ensures concentricity and the dimensional tolerance is 0 to + 0.01 mm.

[0015] Furthermore, in step S4, during the ship installation process, the diesel engine and the shaft system are installed at predetermined positions in the hull, and the outer circles of the diesel engine crankshaft connecting flange and the shaft system connecting flange are aligned to ensure that the diesel engine crankshaft connecting flange and the shaft system connecting flange are concentric, and the connecting holes are pre-aligned, and the expansion bolts are used to expand and accurately position them to complete the connection and assembly.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. It can improve the assembly efficiency of high-power marine diesel engines and shaft systems.

[0018] 2. It can be applied to various crankshaft models of high-power marine diesel engines.

[0019] 3. The drilling template can be used repeatedly, which improves the economy of the operation process and facilitates maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the effect of a high-precision positioning method for a crankshaft and shaft system of a low-speed, high-power marine diesel engine proposed by the present invention;

[0021] Figure 2 It is a structural schematic diagram of the high-precision drilling template in the present invention.

[0022] Among them, the figure marks are: 1-diesel engine crankshaft connecting flange; 2-high-precision drilling template; 21-connecting hole; 22-positioning stop; 3-shaft system connecting flange. DETAILED DESCRIPTION

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] The invention provides a high-precision positioning method for a crankshaft and a shaft system of a low-speed and high-power marine diesel engine, which is suitable for crankshafts of low-speed and high-power marine diesel engines of models S50ME-B to 12G95ME-C.

[0025] like Figure 1 As shown, the method specifically comprises the following steps:

[0026] S1. Prefabricated high-precision drilling template 2: The high-precision drilling template 2 is an annular structure and is made of anti-deformation material to ensure manufacturing accuracy. Positioning stoppers 22 are designed on the inner ring of the outer circumference of the end faces on both sides of the high-precision drilling template 2, and the positioning stoppers 22 on the end faces on both sides are highly coaxial and have high precision, which meets the requirements for high-precision assembly and alignment of the crankshaft and the shaft system. The two sides of the high-precision drilling template 2 are stamped with CS and IS marks for distinction. According to the technical characteristics of the product being used, connection holes 21 evenly distributed around the circumference are designed on the surface of the high-precision drilling template 2, which serve as reference holes for machining and alignment of the connection holes between the diesel engine crankshaft connection flange 1 and the shaft system connection flange 3.

[0027] S2. Precisely position the CS surface of the high-precision drilling template 2 and the diesel engine crankshaft connecting flange 1, and directly process the finished connecting hole; the specific process is as follows: the diesel engine crankshaft connecting flange 1 is processed into a finished product in the previous process, and the surface of the diesel engine crankshaft connecting flange 1 is used as a reference for leveling; the CS surface of the high-precision drilling template 2 and the diesel engine crankshaft connecting flange 1 are highly accurately aligned, and then fixed to ensure that each connecting hole 21 of the high-precision drilling template 2 is aligned with the corresponding connecting hole of the diesel engine crankshaft connecting flange 1; the connecting holes (alignment holes) on the diesel engine crankshaft connecting flange 1 are processed with each connecting hole 21 of the high-precision drilling template 2 as a reference, and the processing ensures concentricity and the dimensional tolerance is guaranteed to be within 0~+0.01mm.

[0028] S3. Precisely position the IS surface of the high-precision drilling template 2 and the shaft connection flange 3, and directly process the finished connecting holes; the specific process is as follows: the shaft connection flange 3 is processed as a finished product in the previous process, and the surface of the shaft connection flange 3 is used as a reference for leveling; the IS surface of the high-precision drilling template 2 and the shaft connection flange 3 are highly accurately aligned, and then fixed to ensure that each connecting hole 21 of the high-precision drilling template 2 is aligned with the corresponding connecting hole of the shaft connection flange 3; the connecting holes (alignment holes) on the shaft connection flange 3 are processed based on the connecting holes of the high-precision drilling template 2, and the processing ensures concentricity and the dimensional tolerance is 0~+0.01mm.

[0029] S4. During ship installation, the diesel engine crankshaft connection flange 1 and the shaft system connection flange 3 are aligned and positioned to complete the connection. The specific process is as follows: During ship installation, the diesel engine crankshaft and the shaft system are installed at the predetermined position in the hull, and the outer circle of the diesel engine crankshaft connection flange 1 and the outer circle of the shaft system connection flange 3 are aligned to ensure that the diesel engine crankshaft connection flange 1 and the shaft system connection flange 3 are concentric, and the connection holes are pre-aligned, and the expansion bolts are used to expand and accurately position them to complete the connection and assembly.

[0030] The weight of a marine diesel engine crankshaft is usually between 45 tons and 539 tons. The diameter of the diesel engine crankshaft and the shaft connection flange is close to 2 meters. It is difficult to connect such a large-tonnage component with high precision.

[0031] The original connection method: the connection holes of the diesel engine crankshaft connection flange and the connection holes of the shaft system connection flange are not directly processed into finished products, but are pre-processed and reserved. The diesel engine and the shaft system are high-precision docked on the hull, and then the processing equipment is used to drill and ream the aligned connection holes into finished products.

[0032] The present invention realizes the connection holes of the diesel engine crankshaft connection flange and the shaft connection flange to be finished separately, ensuring direct connection during hull assembly and ensuring assembly connection accuracy. The difficulty lies in: through this technical solution, ultra-large tonnage and ultra-large diameter connectors can be processed separately and then docked with high precision. It can effectively solve the problem that the size and shape and position tolerance errors of the finished connection holes cannot meet the technical requirements due to processing errors caused by differences in personnel and equipment.

[0033] The working principle of the present invention is: through a high-precision drilling template 2 (with a diameter exceeding φ1900mm), high-precision alignment is performed with the marine low-speed and high-power diesel engine crankshaft connecting flange 1 and the shaft system connecting flange 3 respectively, and high-precision processing of the connecting holes of the connecting flanges of the two is completed, so as to ensure that the marine low-speed and high-power diesel engine crankshaft and the shaft system are assembled with high precision during the hull assembly, and the current drilling and reaming process after the flange connecting holes are connected can be omitted, thereby greatly improving the assembly efficiency.

[0034] Matters not described in detail in the present invention are all known technologies.

[0035] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for high-precision positioning of the crankshaft and shaft system of a low-speed, high-power marine diesel engine, characterized in that: The method comprises the following steps: S1, prefabricated high-precision drilling template, with CS and IS marks printed on both sides of the drilling template; S2. Precisely position the CS surface of the high-precision drilling template and the diesel engine crankshaft connection flange, and directly process the connection hole product; S3. Precisely position the IS surface of the high-precision drilling template and the shaft connection flange, and directly process the connection hole product; S4. During installation on board a ship, align the diesel engine crankshaft connection flange with the shaft connection flange to complete the finished product assembly.

2. A method for high-precision positioning of a crankshaft and shaft system of a low-speed, high-power marine diesel engine according to claim 1, characterized in that: In step S1, positioning stoppers are provided on both sides of the high-precision drilling template, and the stoppers have the same axiality; the surface of the high-precision drilling template is designed with evenly distributed connecting holes, which serve as reference holes for machining and aligning the connecting holes of the crankshaft and the shaft system.

3. A method for high-precision positioning of a crankshaft and shaft system of a low-speed, high-power marine diesel engine according to claim 1 or 2, characterized in that: The high-precision drilling template is made of anti-deformation material.

4. A method for high-precision positioning of a crankshaft and shaft system of a low-speed, high-power marine diesel engine according to claim 2, characterized in that: In the step S2, after the diesel engine crankshaft connecting flange is processed into a finished product in the previous process, the diesel engine crankshaft connecting flange surface is used as a reference for leveling; the high-precision drilling template CS surface and the diesel engine crankshaft connecting flange are aligned with high precision, and then fixed to ensure that each connecting hole of the high-precision drilling template is aligned with the corresponding connecting hole of the diesel engine crankshaft; the diesel engine crankshaft connecting flange alignment holes are processed based on each connecting hole of the high-precision drilling template, and the processing ensures concentricity and the dimensional tolerance is guaranteed to be within 0 to +0.01mm.

5. A method for high-precision positioning of a crankshaft and shaft system of a low-speed, high-power marine diesel engine according to claim 4, characterized in that: In the step S3, the shaft connection flange is processed into a finished product in the previous process, and the shaft connection flange surface is used as a reference for leveling; the IS surface of the high-precision drilling template and the shaft connection flange are aligned with high precision, and then fixed to ensure that each connection hole of the high-precision drilling template is aligned with the corresponding connection hole of the shaft system; the shaft connection flange alignment holes are processed based on the connection holes of the high-precision drilling template, and the processing ensures concentricity and the dimensional tolerance is guaranteed to be 0 to + 0.01 mm.

6. A method for high-precision positioning of a crankshaft and shaft system of a low-speed, high-power marine diesel engine according to claim 5, characterized in that: In step S4, during the ship installation process, the diesel engine and the shaft system are installed at a predetermined position in the hull, and the outer circle of the diesel engine crankshaft connecting flange and the outer circle of the shaft system connecting flange are aligned to ensure that the diesel engine crankshaft connecting flange and the shaft system connecting flange are concentric, and the connecting holes are pre-aligned, and the expansion bolts are used to expand and accurately position them to complete the connection and assembly.

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