Cylinder cover stud positioning method during mounting of marine low-speed diesel engine lifting appliance

Abstract

According to the method for positioning the cylinder cover studs during installation of the marine low-speed diesel engine lifting appliance, when a cylinder cover is installed on a cylinder body, before the cylinder cover nuts are tightly pumped, a positioning device is arranged on all the cylinder cover studs and the cylinder cover nuts in a penetrating mode at the same time, and a plurality of positioning holes are formed in the positioning device and used for allowing the cylinder cover studs and the cylinder cover nuts to penetrate through; the position of the positioning device is the same as that of a mounting hole in the lower plane of the lifting appliance, the hole diameter of the positioning device is matched with the outer diameter of a cylinder cover nut, the positioning of each cylinder cover stud is realized through the limiting effect of the positioning device on the cylinder cover nut, and then under the positioning effect of the positioning device, the cylinder cover nut is tightly pumped so as to keep the positioning of the cylinder cover stud. Therefore, all cylinder cover studs can penetrate into the mounting holes of the lifting appliance at the same time, and the lifting appliance can be smoothly mounted and fixed on the cylinder body. According to the invention, the possible installation interference condition can be identified in advance, the installation efficiency is improved, the production period is shortened, the production cost is reduced, the device has the advantages of simple structure and convenience in operation, and favorable conditions are created for the subsequent installation of the lifting appliance.

Description

Technical Field

[0001] The present invention relates to the assembly process of marine diesel engines, and particularly to a positioning method for cylinder head studs during the installation of a lifting tool for a marine low-speed diesel engine, belonging to the technical field of diesel engine manufacturing. Background Art

[0002] With the continuous development of the shipping industry, the demand for marine diesel engine products has also increased significantly. Diesel engine factories and shipyards need to compress time and improve efficiency during diesel engine disassembly and assembly to better meet market demands. After the marine diesel engine is tested on the test bench at the main engine factory, it needs to be disassembled from the test bench, lifted, and shipped. Some larger models need to be disassembled into three parts: the engine base, the engine frame, and the cylinder block, and then lifted separately. The lifting of the cylinder block part is usually achieved by borrowing a special lifting tool.

[0003] As is well known, the cylinder head is fixed to the cylinder block by cylinder head studs. Please refer to Figure 1 , multiple vertical cylinder head studs 2 are fixedly connected to the cylinder block. There are a plurality of cylinder head stud holes on the cylinder head 1 corresponding to the positions of the cylinder head studs 2. When installing the cylinder head 1, align the cylinder head stud holes on the cylinder head 1 with the cylinder head studs 2, lower the cylinder head 1 to cover the cylinder block, then connect the cylinder head nuts 3 to the cylinder head studs 2, and finally pump the cylinder head nuts 3 tightly with a hydraulic tensioner to fix the cylinder head 1 on the cylinder block.

[0004] The lifting tool used for lifting the cylinder block is connected to the cylinder block by borrowing the cylinder head studs 2. Similar to the cylinder head 1, the lower part of the lifting tool is provided with a plurality of installation holes at the same positions as the cylinder head studs 2. To avoid interference caused by the cylinder head 1, the contour shape of the lower plane of the cylinder block lifting tool is an irregular special shape to avoid the upward convex part of the cylinder head 1 and cover all the installation holes inside. When installing the lifting tool, first align the installation holes on the lifting tool with the cylinder head studs 2, lower the lifting tool, then pump the installation nuts tightly with a hydraulic tensioner to fix the lifting tool on the cylinder block and the cylinder head 1, and finally connect the lifting tool with a hook to start the cylinder block lifting operation.

[0005] The positions and sizes of the installation holes on the lifting tool are processed according to the standards designed in the drawings. Since the cylinder head stud holes are slightly larger than the cylinder head studs 2, the actual positions (including the center distance, etc.) of each cylinder head stud 2 after the cylinder head 1 is tightly installed will deviate from the standard positions. Especially for the longer cylinder head studs 2, which protrude above the cylinder head 1 by a relatively large height, the bending and deformation of the cylinder head studs 2 along the axial direction will further increase this position deviation. Therefore, when installing the lifting tool, it often occurs that the multiple installation holes of the lifting tool cannot all match the cylinder head studs 2, and often one or two of the multiple cylinder head studs 2 cannot be aligned and inserted into the installation holes of the lifting tool. Once this situation occurs, corrective measures must be taken for the cylinder head studs 2 with position deviations and assembly interferences, and after the position is calibrated, the installation of the lifting tool is continued.

[0006] The above installation method of the sling will not only waste a lot of man-hours of the equipment for lifting the sling, increase the rework manpower and time, reduce the efficiency of the cylinder block lifting operation, but also delay the production cycle and increase the production cost. Summary of the Invention

[0007] The purpose of the present invention is to overcome the difficulties in the installation process of the existing sling, and provide a positioning method for the cylinder head studs during the installation of the sling for a marine low-speed diesel engine. Before the installation of the sling, with the help of a positioning device, the actual positions of the cylinder head studs are verified and positioned, creating favorable conditions for the installation of the sling, so that the sling and the cylinder head studs can be accurately aligned, so that before the cylinder block lifting operation, the sling can be installed safely, efficiently and conveniently, and the disassembly and shipping work after the commissioning of the marine low-speed diesel engine can be successfully completed.

[0008] To achieve the above purpose, the technical solution of the present invention is as follows:

[0009] A positioning method for cylinder head studs during the installation of a sling for a marine low-speed diesel engine. The diesel engine includes a cylinder head and a cylinder block connected by cylinder head studs and cylinder head nuts. A plurality of cylinder head studs are fixedly connected to the cylinder block. The sling is used to connect and lift the cylinder block and the cylinder head, and a plurality of mounting holes with standard sizes and positions are opened on the lower plane. The mounting holes are used to pass through the cylinder head studs. It is characterized in that: when the cylinder block installs the cylinder head, before the cylinder head nut is tightened, the positioning device is simultaneously passed through all the cylinder head studs and the cylinder head nuts, and the positioning of the positions of the cylinder head studs is realized through the limiting action of the positioning device on the cylinder head nuts. Then, under the positioning action of the positioning device, the cylinder head nuts are tightened to maintain the positioning of the cylinder head studs, so as to ensure that the mounting holes of the sling can simultaneously penetrate all the cylinder head studs, and the installation and fixation of the sling on the cylinder block are successfully completed.

[0010] Further, the mounting holes with standard sizes and positions refer to: mounting holes whose sizes and positions meet the design technical requirements.

[0011] Further, the positioning device is a flat plate, and a plurality of positioning holes are opened on it for passing through the cylinder head studs and the cylinder head nuts. The positioning holes are through holes, and the positions are the same as the mounting holes on the lower plane of the sling, and the diameter sizes are matched with the outer diameters of the cylinder head nuts.

[0012] Further, the diameter of the positioning hole forms a clearance fit with the outer diameter of the cylinder head stud.

[0013] Further, the contour shape of the positioning device is the same as that of the lower plane of the sling, and it is an irregular special shape to avoid the upward convex part of the cylinder head.

[0014] Further, the positioning method includes the following specific steps:

[0015] 1) Fabricate the positioning device so that the position of the positioning hole is exactly the same as the mounting hole on the lower plane of the sling, and the diameter of the positioning hole is matched with the outer diameter of the cylinder head nut;

[0016] 2) When installing the cylinder head on the cylinder block, first do not tighten the cylinder head nut, but simultaneously pass the positioning hole of the positioning device through all the cylinder head studs and cylinder head nuts, and position the positions of the cylinder head studs through the restrictive effect of the positioning hole on the cylinder head nut;

[0017] 3) Under the positioning action of the positioning device, use a hydraulic tensioner to tighten all the cylinder head nuts, so as to maintain the positioning of the positioning device on the cylinder head studs;

[0018] 4) Align the mounting hole on the sling with the cylinder head studs, ensure that all the cylinder head studs can simultaneously pass through the mounting hole on the sling, then lower the sling, and use a hydraulic tensioner to pump and fix the sling on the cylinder block and cylinder head to complete the installation of the sling.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1) The present invention uses a positioning device to pre-verify the actual position of the cylinder head studs, realizes the early identification of possible installation interference conditions, and can thus take adjustment measures in a timely manner, creating favorable conditions for the subsequent installation of the sling.

[0021] 2) By using the positioning device, the positioning of the sling installation can be completed while tightening the cylinder head nuts, avoiding the possibility of having to interrupt the sling installation operation and then carry out adjustment work subsequently, thereby improving the installation efficiency, shortening the production cycle, and reducing the production cost.

[0022] 3) The present invention optimizes the technological process of the sling installation operation. The positioning device has a simple structure and is easy to operate, without the need for additional complex equipment or operating techniques, simplifies the operation, and improves the efficiency of the sling installation operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a diagram of the installation and use state of the present invention.

[0024] Figure 2 is a schematic diagram of the positioning device.

[0025] In the figure,

[0026] 1 - cylinder head, 2 - cylinder head stud, 3 - cylinder head nut, 4 - positioning device, 41 - flat bottom plate, 42 - positioning hole. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. However, the following embodiments are not used to limit the scope of implementation of the present invention. Any equivalent replacement and modification made based on the content of this specification shall fall within the scope of protection required by the present invention.

[0028] The present invention is used for positioning the cylinder head studs during the installation of a marine low-speed diesel engine lifting tool. Please refer to Figure 1 , the diesel engine includes a cylinder head 1 and a cylinder block connected by cylinder head studs 2 and cylinder head nuts 3, and multiple cylinder head studs 2 are fixedly connected to the cylinder block. The lifting tool is used to connect and lift the cylinder block and the cylinder head 1, and its lower plane is provided with a plurality of mounting holes with standard sizes and positions, that is, mounting holes that meet the technical requirements of the drawing design in terms of size and position. These mounting holes are used to pass through the cylinder head studs 2; the contour shape of the lower plane of the lifting tool is an irregular special shape to avoid the upward convex part of the cylinder head, so as to prevent interference during the installation of the lifting tool.

[0029] Please refer to Figure 2 , the positioning device 1 is a flat bottom plate 41, which is provided with a plurality of positioning holes 42. The contour shape of the flat bottom plate 41 is the same as that of the lower plane of the lifting tool, which is an irregular special shape to avoid the upward convex part of the cylinder head. The positioning holes 42 are through holes, which are used to pass through the cylinder head studs 2 and the cylinder head nuts 3; the positions of the positioning holes 42 are the same as those of the mounting holes on the lower plane of the lifting tool, so as to position the cylinder head studs 2. The diameter dimension of the positioning holes 42 forms a clearance fit with the outer diameter of the cylinder head nut 3 to limit the position of the cylinder head nut 3.

[0030] When installing the cylinder head 1 on the cylinder block, before the cylinder head nut 3 is tightened, first pass the positioning device 4 through all the cylinder head studs 2 and the cylinder head nuts 3 at the same time. Through the limiting effect of the positioning holes 42 of the positioning device 4 on the cylinder head nut 3, the positions of the cylinder head studs 2 are positioned; then under the positioning effect of this positioning device, the cylinder head nut 3 is tightened to maintain the positioning of the cylinder head studs 2, so as to ensure that when the lifting tool is installed, its mounting holes can penetrate all the cylinder head studs 2 at the same time, and the installation and fixation of the lifting tool on the cylinder block are successfully completed.

[0031] The method for positioning the cylinder head studs during the installation of the lifting tool includes the following specific steps:

[0032] 1) Manufacture the positioning device 4 so that the positions of its positioning holes 42 are exactly the same as those of the mounting holes on the lower plane of the lifting tool, and the diameter of the positioning holes 42 is matched with the outer diameter of the cylinder head nut 3;

[0033] 2) When installing the cylinder head 1 on the cylinder block, instead of tightening the cylinder head nuts 3 first, the positioning holes 42 of the positioning device are first simultaneously placed over all the cylinder head studs 2 and cylinder head nuts 3 where the lifting tools need to be installed, and the positions of the cylinder head studs 2 are positioned through the restrictive effect of the positioning holes 42 on the outer circle of the cylinder head nuts 3;

[0034] 3) Under the positioning effect of the positioning device 4, a hydraulic tensioner is used to tighten all the cylinder head nuts 3, so as to maintain the positioning of the positioning device on the cylinder head studs 2, and the positioning device 4 plays a role in restricting the displacement of the cylinder head nuts 3 during the tightening process;

[0035] 4) Align the positioning holes 42 on the lifting tool with the cylinder head studs 2 to ensure that all the cylinder head studs 2 can simultaneously pass through the mounting holes on the lifting tool, then lower the lifting tool, and use a hydraulic tensioner to tighten and fix the lifting tool on the cylinder block and the cylinder head 1, thereby completing the installation of the lifting tool.

[0036] The above is only a preferred embodiment of the present invention and is not used to limit the scope of the present invention. That is, all equivalent changes and modifications made according to the content of the present invention should fall within the technical scope of the present invention.

Claims

1. A positioning method for cylinder head studs during the installation of a marine low-speed diesel engine lifting tool. The diesel engine includes a cylinder head and a cylinder block connected by cylinder head studs and cylinder head nuts. A plurality of cylinder head studs are fixedly connected to the cylinder block. The lifting tool is used to connect and lift the cylinder block and the cylinder head, and a plurality of mounting holes with standard sizes and positions are opened on the lower plane. The mounting holes are used to pass through the cylinder head studs; it is characterized in that: When installing the cylinder head on the cylinder block, before tightening the cylinder head nuts, the positioning device is simultaneously inserted through all the cylinder head studs and cylinder head nuts. The positioning of the positions of the cylinder head studs is achieved through the restrictive effect of the positioning device on the cylinder head nuts. Then, under the positioning effect of the positioning device, the cylinder head nuts are tightened to maintain the positioning of the cylinder head studs, so as to ensure that the mounting holes of the lifting tool can simultaneously penetrate all the cylinder head studs and smoothly complete the installation and fixation of the lifting tool on the cylinder block.

2. The positioning method of the cylinder head stud during the installation of the lifting device for marine low-speed diesel engines according to claim 1, characterized in that: The mounting holes with the specified standard size and position refer to the mounting holes whose size and position meet the design technical requirements.

3. The positioning method of the cylinder head studs during the installation of the lifting tool for marine low-speed diesel engines according to claim 1, characterized in that: The positioning device is a flat plate with a plurality of positioning holes opened thereon for inserting the cylinder head studs and cylinder head nuts. The positioning holes are through holes, and their positions are the same as the mounting holes on the lower plane of the lifting tool, and the diameter size is matched with the outer diameter of the cylinder head nut.

4. The positioning method of the cylinder head stud during the installation of the marine low-speed diesel engine sling according to claim 3, characterized in that: The diameter of the positioning hole forms a clearance fit with the outer diameter of the cylinder head nut.

5. The positioning method of the cylinder head stud during the installation of the lifting device for marine low-speed diesel engines according to claim 1 or 3, characterized in that: The positioning device has the same contour shape as the lower plane of the lifting tool, which is an irregular special shape to avoid the upward convex part of the cylinder head.

6. The positioning method of the cylinder head studs during the installation of the lifting tool for marine low-speed diesel engines according to claim 3, characterized in that: The positioning method includes the following specific steps: 1) Fabricate the positioning device so that the position of the positioning hole is precisely the same as the mounting hole on the lower plane of the lifting tool, and the diameter of the positioning hole is matched with the outer diameter of the cylinder head nut; 2) When installing the cylinder head on the cylinder block, first do not tighten the cylinder head nuts, but insert the positioning holes of the positioning device through all the cylinder head studs and cylinder head nuts at the same time, and position the positions of the cylinder head studs through the restrictive effect of the positioning holes on the cylinder head nuts; 3) Under the positioning effect of the positioning device, use a hydraulic tensioner to tighten all the cylinder head nuts, so as to maintain the positioning of the positioning device on the cylinder head studs; 4) Align the mounting holes on the lifting tool with the cylinder head studs to ensure that all the cylinder head studs can simultaneously penetrate the mounting holes on the lifting tool. Then lower the lifting tool and use a hydraulic tensioner to tighten and fix the lifting tool on the cylinder block and the cylinder head to complete the installation of the lifting tool.

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