A tooling for piston assembly installation

Abstract

This application discloses a tooling for installing a piston assembly. The tooling tube has a tapered hole. When the piston assembly is installed inside the cylinder block using this tooling, the piston assembly is inserted from the first end with a larger inner diameter of the tapered hole. Because the inner diameter of the first end is larger than the installation size of the piston assembly, it is easier for the piston assembly to be inserted into the tapered hole. When an external force is used to push the piston assembly to move along the tube, the diameter of the piston assembly is gradually compressed as it moves in the tapered hole. Because the inner diameter of the second end is smaller than or equal to the installation size of the piston assembly, when the piston assembly moves to the second end, the diameter of the piston assembly is compressed to be smaller than or equal to the installation size of the piston assembly. In this way, the piston assembly can smoothly enter the cylinder bore of the cylinder block, thus realizing the installation of the piston assembly.

Description

Technical Field

[0001] This application relates to the field of engine assembly technology, and in particular to a tooling for piston assembly installation. Background Technology

[0002] The installation of the piston and connecting rod assembly is a critical step in engine manufacturing. Please refer to [reference needed]. Figure 1 The existing tooling for piston connecting rod assembly installation uses two semi-circular tubes: a first semi-circular tube 1' and a second semi-circular tube 2'. The two semi-circular tubes are tightened with bolts 3' to achieve cylindrical structure docking to compress the piston rings, making their diameter smaller than the cylinder bore diameter before installation. The bottom of the tooling is positioned with the cylinder bore through an extended thin-walled mechanism (positioning lip) to achieve installation guidance.

[0003] However, the existing solution has obvious drawbacks. Because the piston rings are compressed by tightening the bolts by 3', the whole process takes a long time. For example, the estimated cycle time for installing 4 pistons is 64s (6s to tighten all 2 bolts, 4s to install a single piston into the cylinder, and 6s to remove 2 bolts), which is not suitable for mass production lines.

[0004] Overcoming the aforementioned shortcomings is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] The purpose of this application is to provide a tooling for piston assembly installation that can improve engine assembly efficiency while reducing production costs.

[0006] This application provides a tooling for mounting a piston assembly, including a tube body. The tube body includes a first tube segment with a tapered bore. Along the insertion direction of the piston assembly, the first tube segment includes a first end and a second end. The inner diameter of the first end is larger than the mounting size of the piston assembly, and the inner diameter of the second end is less than or equal to the mounting size. The mounting size is the cylinder bore diameter of the cylinder body that mates with the piston assembly.

[0007] When using this tool to install the piston assembly inside the cylinder block, the piston assembly is inserted from the first end of the tapered bore, which has a larger inner diameter. Because the inner diameter of the first end is larger than the installation size of the piston assembly, it is easier for the piston assembly to be inserted into the tapered bore. Using external force to push the piston assembly along the tube, the diameter of the piston assembly is gradually compressed as it moves in the tapered bore. Because the inner diameter of the second end is smaller than or equal to the installation size of the piston assembly, when the piston assembly moves to the second end, the diameter of the piston assembly is compressed to be smaller than or equal to the installation size of the piston assembly. In this way, the piston assembly can smoothly enter the cylinder bore of the cylinder block, thus realizing the installation of the piston assembly.

[0008] In one example, the pipe body further includes a second pipe segment, which is coaxially arranged with the first pipe segment and connected to the second end of the first pipe segment. The inner hole of the second pipe segment is a cylindrical hole of equal diameter, and the diameter of the cylindrical hole is less than or equal to the installation dimension.

[0009] In one example, the connection between the inner wall of the first pipe segment and the inner wall of the second pipe segment is a smooth transition surface.

[0010] In one example, the wall thickness of the second pipe segment is less than or equal to the wall thickness of the first pipe segment.

[0011] In one example, the outer peripheral wall of the end of the second pipe segment away from the first pipe segment is further provided with a radially extending protrusion, the maximum outer diameter of which is greater than the cylinder bore diameter.

[0012] In one example, the outer contour of the protrusion in the radial section is a semi-circular arc, and the end of the semi-circular arc away from the first pipe segment is connected to the end face of the second pipe segment.

[0013] In one example, the wall surrounding the conical hole includes a first conical surface and a second conical surface that are in contact. The first conical surface and the second conical surface are arranged along the insertion direction. The angle between the generatrix extension direction of the first conical surface and the axial direction of the tube body is a first angle, and the angle between the generatrix extension direction of the second conical surface and the axial direction of the tube body is a second angle. The first angle is greater than the second angle.

[0014] In one example, the second included angle ranges from 7° to 8°; the first included angle ranges from 10° to 16°.

[0015] In one example, the outer wall of the tube is provided with an anti-slip structure.

[0016] In one example, the pipe body includes a main pipe and a wear-resistant layer disposed on the inner wall of the main pipe. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the tooling used for piston assembly installation in current technology;

[0018] Figure 2 This is a schematic diagram of the tooling used for piston assembly installation in one embodiment of this application;

[0019] Figure 3 for Figure 2 A schematic diagram of the axial cross-section of the tooling shown;

[0020] Figure 4 for Figure 3 A magnified view of a portion of the cross-sectional diagram shown.

[0021] in, Figures 1 to 4 The one-to-one correspondence between the reference numerals and component names in the attached drawings is as follows:

[0022] 1' First semicircular tube; 2' Second semicircular tube; 3' Bolt;

[0023] 1 Pipe body; 11 First pipe section; 111 Conical hole; 11A First conical surface; 11B Second conical surface; 112 Anti-slip structure; 12 Second pipe section; 12A Cylindrical hole; 13 Transition surface; b Difference; d1 First included angle; d2 included angle; 1-1 Main pipe; 1-2 Wear-resistant layer. Detailed Implementation

[0024] For example, this application describes the technical solution and technical effect by using the tooling provided in this application to install the piston connecting rod assembly into the cylinder block of an engine. Those skilled in the art should understand that the tooling provided in the embodiments of this application can install the piston connecting rod assembly into the cylinder block of other mechanisms and achieve the same or equivalent technical effect as this application.

[0025] Please refer to Figures 2 to 4 , Figure 2 This is a schematic diagram of the tooling used for mounting a piston connecting rod assembly in one embodiment of this application; Figure 3 for Figure 2 A schematic diagram of the axial cross-section of the tooling shown; Figure 4 for Figure 3 A magnified view of a portion of the cross-sectional diagram shown.

[0026] This application provides a tooling for mounting a piston assembly. The piston assembly typically includes a piston body and piston rings fitted circumferentially around the piston body. The piston body usually has one or more annular grooves machined on it, and one piston ring is installed inside each annular groove. The outer diameter of the piston ring is typically larger than the outer diameter of the piston body. The number of piston rings can be one or more. Piston rings are divided into compression rings and oil rings. Compression rings are responsible for sealing the combustion chamber of the cylinder, preventing gas leakage and ensuring combustion efficiency. Oil rings keep the inside of the crankcase clean and prevent oil loss. Using the tooling provided in this application, the outer diameter of the piston assembly can be compressed to or smaller than the mounting size for installation into the engine block. In this application, "mounting size" refers to the cylinder bore diameter of the cylinder block that mates with the piston assembly.

[0027] The tooling includes a tube body 1, which is a hollow tube structure with openings at both ends. The two openings are the inlet and the outlet, respectively. The larger opening is the inlet and the smaller opening is the outlet. The piston assembly is inserted into the tube body 1 through the inlet and moves from the inlet to the outlet under the action of external force. During the movement, the outer diameter of the piston assembly is compressed. When the piston assembly moves to the outlet position, the piston assembly is compressed to a size that meets or is smaller than the assembly requirements, so that the piston assembly can be easily assembled into the cylinder.

[0028] In this embodiment, the tube body 1 includes a first tube segment 11 with a tapered hole. Along the insertion direction f of the piston assembly, the first tube segment 11 includes a first end and a second end. The inner diameter of the first end is larger than the inner diameter of the second end. That is, along the insertion direction f of the piston assembly, the diameter of the tapered hole 111 tends to decrease. In this embodiment, the inner diameter of the second end is less than or equal to the installation size of the piston assembly, and the inner diameter of the first end is larger than the installation size of the piston assembly.

[0029] When using this tool to install the piston assembly inside the cylinder, the piston assembly is inserted from the first end of the tapered bore 111, which has a larger inner diameter. Because the inner diameter of the first end is larger than the installation size of the piston assembly, it is easier for the piston assembly to be inserted into the tapered bore 111. Using external force to push the piston assembly to move along the tube 1, the diameter of the piston assembly is gradually compressed as it moves in the tapered bore 111. Because the inner diameter of the second end is smaller than or equal to the installation size of the piston assembly, when the piston assembly moves to the second end, the diameter of the piston assembly is compressed to be smaller than or equal to the installation size of the piston assembly. In this way, the piston assembly can smoothly enter the cylinder bore of the cylinder and realize the installation of the piston assembly.

[0030] The piston assembly mounting fixture provided in this application has a one-piece tube body 1. By utilizing the size variation of the tapered hole 111, the piston assembly can be inserted into the tube body 1 and the diameter of the piston assembly can be compressed. There is no need to assemble or disassemble the tube body 1 on site, which saves assembly efficiency, improves the overall production line efficiency, and the manufacturing cost of the fixture is relatively low.

[0031] In this embodiment, the pipe body 1 further includes a second pipe segment 12, the length L of which can be reasonably set according to the specific product. The first pipe segment 11 and the second pipe segment 12 are coaxially arranged, and the second pipe segment 12 is connected to the second end of the first pipe segment 11. The inner hole of the second pipe segment 12 is a cylindrical hole 12A of equal diameter, meaning that the diameters are equal. The diameter of the cylindrical hole 12A is less than or equal to the installation size of the piston assembly. Compared with the tapered hole 111, the cylindrical hole 12A has better axial guiding capability. This ensures that the piston assembly moves axially, which is beneficial for the piston assembly to smoothly enter the cylinder body axially. On the other hand, the second pipe segment 12 is a cylindrical hole 12A with a constant diameter, which can better compress the piston assembly as a whole, further facilitating its smooth entry into the cylinder body.

[0032] In this embodiment, the connection position of the first pipe segment 11 and the second pipe segment 12 can be a smooth transition surface 13, which ensures that the piston assembly can pass through the connection position without jamming. The piston assembly can smoothly enter the interior of the cylindrical hole 12A from the tapered hole 111. The force between the piston assembly and the inner wall of the pipe body 1 is also relatively small, which is beneficial to protecting the surface of the piston assembly.

[0033] In this embodiment, in addition to the frictional force from the piston assembly, the peripheral wall of the first pipe segment 11 is also subjected to some external force (the force that drives the piston assembly). Compared to the first pipe segment 11, the force on the peripheral wall of the second pipe segment 12 is basically the frictional force from the piston assembly, which is relatively small. Therefore, the wall thickness of the second pipe segment 12 can be less than or equal to the wall thickness of the first pipe segment 11. Here, the comparison between the wall thickness of the first pipe segment 12 and the wall thickness of the first pipe segment 11 is based on an ideal state. However, considering factors such as errors in the manufacturing process, it is possible that the wall thickness of a local location in the first pipe segment 11 may be less than the thickness of a local location in the second pipe segment 12. This can save on the manufacturing cost of the tooling, and the tooling is relatively lightweight.

[0034] In one example, the wall thickness S of the first pipe section 11 can be greater than or equal to 2.5 mm, and the wall thickness of the second pipe section 12 can be any value between approximately 2 mm and 2.5 mm. This makes the pipe body 1 relatively lightweight.

[0035] In this embodiment, the outer peripheral wall of the end of the second pipe segment 12 away from the first pipe segment 11 is further provided with a radially extending protrusion 121. The maximum outer diameter of the protrusion 121 is greater than the cylinder bore diameter. The protrusion 121 can be arranged in a ring along the outer peripheral wall of the second pipe segment 12, that is, the protrusion 121 is a continuous ring structure. The ring structure forming process is relatively simple. The number of protrusions 121 can also be multiple. Multiple protrusions 121 are arranged circumferentially along the outer peripheral wall, and the product structure weight is relatively light.

[0036] In this embodiment, the tooling can be supported on the end face of the cylinder by the protrusion 121, which is conducive to the docking of the tooling and the cylinder, so that the piston assembly can smoothly enter the cylinder bore of the cylinder.

[0037] In this embodiment, the outer contour of the protrusion 121 in the radial section is a semi-circular arc. In this application, the cross section is a plane perpendicular to the central axis of the pipe body 1, and the radial section is a plane perpendicular to the cross section. The semi-circular arc is connected to the end face of the second pipe segment 12 away from the first pipe segment 11.

[0038] In this embodiment, the diameter change rate of the conical hole can be the same along the axial direction. Of course, the conical hole can also include multiple holes with different diameter change rates along the axial direction. In one embodiment, the wall forming the conical hole includes a first conical surface 11A and a second conical surface 11B that are in contact. The first conical surface 11A and the second conical surface 11B are arranged along the insertion direction f. The angle between the extension of the generatrix of the first conical surface 11A and the axial direction of the tube body 1 is a first angle d1, and the angle between the extension of the generatrix of the second conical surface 11B and the axial direction of the tube body 1 is a second angle d. The first angle d1 is greater than the second angle d. Figure 3 The difference b between the first included angle d1 and the second included angle d is shown, where b = d1 - d. In this way, while ensuring that the piston assembly can be smoothly inserted into the opening position of the first end, the overall length of the tube body 1 is relatively short, and the manufacturing cost of the tooling is relatively low.

[0039] In this embodiment, the second included angle d can range from 7° to 8°, for example, 7°, 7.2°, 7.4°, 7.5°, 7.6°, 7.8°, or 8°; of course, the second included angle d can be any value between 7° and 8°. The first included angle can range from 10° to 16°, for example, 10°, 11°, 12°, 13°, 14°, 15°, or 16°; of course, the first included angle d1 can be any value between 10° and 16°. When the first included angle d1 and the second included angle d2 are within the above ranges, they can basically meet the installation requirements of most piston assemblies. The tooling can be applied to the installation needs of many types of piston assemblies, has a wide range of applications, and the tooling has good versatility for various types of piston assemblies.

[0040] In this embodiment, the outer wall of the tooling tube 1 is provided with an anti-slip structure 112. The anti-slip structure 112 can be a textured surface with concave and convex structures, or it can be a material layer with high friction on the outer wall of the tube 1, such as adding a friction sleeve to the outer wall of the tube 1. (See attached document for details.) Figure 2 The illustration shows a specific embodiment of the anti-slip structure 112 having a textured surface, which is simple to process and saves costs.

[0041] In one specific embodiment, the tube body 1 includes a main pipe 1-1 and a wear-resistant layer 1-2. The wear-resistant layer 1-2 is disposed on the inner wall of the main pipe 1-1. That is, the walls of the tapered hole and the cylindrical hole 12A mentioned above are both covered with the wear-resistant layer 1-2. The hardness of the wear-resistant layer 1-2 can be higher than that of the main pipe 1-1. Thus, the contact surface between the tube body 1 and the piston assembly is formed by the wear-resistant layer 1-2, which can improve the wear resistance and oxidation resistance of the tube body 1 and increase its service life.

[0042] The main pipe 1-1 can be a metal pipe, and the material of the metal pipe can be cast iron, with the material's hardness ensured through heat treatment. Of course, the metal pipe can also be made of other materials that can meet the strength requirements for use.

[0043] The wear-resistant layer 1-2 can be made of materials with high hardness, high temperature resistance, and high oxidation resistance, such as titanium aluminum nitride, titanium nitride, titanium carbonitride, aluminum nitride, or their titanium-aluminum alloys. Among these, titanium aluminum nitride has relatively high hardness and excellent resistance to high temperatures, oxidation, and corrosion. In one example, the wear-resistant layer 1-2 can be a coating, such as an titanium aluminum nitride coating, titanium nitride coating, titanium carbonitride coating, aluminum nitride coating, or titanium-aluminum alloy coating. The coating can be applied to the main pipe 1-1 by spraying or brushing. The coating thickness is relatively thin, and the tooling weight is also relatively light.

[0044] For piston assemblies with skirt structures, in this embodiment, the outlet of the tube 1 does not need to be provided with a guide positioning structure. It can smoothly enter the cylinder using the skirt structure at the end of the piston assembly, making the tooling structure simpler.

[0045] In the description of embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0046] In the embodiments of this application, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0047] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A tooling for mounting a piston assembly, characterized in that, Includes a tube body (1), the tube body (1) including a first tube segment (11) having a tapered hole (111) along the insertion direction of the piston assembly, the first tube segment (11) including a first end and a second end, the inner diameter of the first end being greater than the mounting size of the piston assembly, and the inner diameter of the second end being less than or equal to the mounting size, wherein the mounting size is the cylinder bore diameter of the cylinder body that mates with the piston assembly.

2. The tooling for piston assembly installation according to claim 1, characterized in that, The pipe body (1) further includes a second pipe section (12), which is coaxially arranged with the first pipe section (11). The second pipe section (12) is connected to the second end of the first pipe section (11). The inner hole of the second pipe section (12) is a cylindrical hole (12A) of equal diameter, and the diameter of the cylindrical hole (12A) is less than or equal to the installation size.

3. The tooling for piston assembly installation according to claim 2, characterized in that, The connection between the inner wall of the first pipe section (11) and the inner wall of the second pipe section (12) is a smooth transition surface.

4. The tooling for piston assembly installation according to claim 2, characterized in that, The wall thickness of the second pipe section (12) is less than or equal to the wall thickness of the first pipe section (11).

5. The tooling for piston assembly installation according to claim 2, characterized in that, The outer peripheral wall of the end of the second pipe section (12) away from the first pipe section (11) is also provided with a radially extending protrusion (121), the maximum outer diameter of the protrusion (121) being greater than the cylinder bore diameter.

6. The tooling for piston assembly installation according to claim 5, characterized in that, The outer contour of the protrusion (121) in the radial section is a semi-circular arc, and the end of the semi-circular arc away from the first pipe section (11) is connected to the end face of the second pipe section (12).

7. The tooling for piston assembly installation according to claim 1, characterized in that, The wall surface forming the conical hole (111) includes a first conical surface (11A) and a second conical surface (11B) that are in contact. The first conical surface (11A) and the second conical surface (11B) are arranged along the insertion direction. The angle between the generatrix extension direction of the first conical surface (11A) and the axial direction of the tube body (1) is a first angle (d1). The angle between the generatrix extension direction of the second conical surface (11B) and the axial direction of the tube body (1) is a second angle (d). The first angle (d1) is greater than the second angle (d).

8. The tooling for piston assembly installation according to claim 7, characterized in that, The second included angle (d) ranges from 7° to 8°; the first included angle ranges from 10° to 16°.

9. The tooling for piston assembly installation according to claim 1, characterized in that, The outer wall of the tube (1) is provided with an anti-slip structure.

10. The tooling for piston assembly mounting according to any one of claims 1 to 9, characterized in that, The pipe body (1) includes a main pipe (1-1) and a wear-resistant layer (1-2), wherein the wear-resistant layer (1-2) is disposed on the inner wall of the main pipe (1-1).

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