A piston installation tool
By designing a piston installation tool that connects a tapered guide hole section with a cylindrical through hole, the problems of large size and piston ring detachment in traditional tools were solved, achieving the effects of reducing costs and improving yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHONGQING WEICHAI ENGINE FACTORY
- Filing Date
- 2025-05-09
- Publication Date
- 2026-05-26
AI Technical Summary
Traditional piston installation tools are bulky, have high production costs, and lack real-time monitoring mechanisms, which can cause piston rings to detach from the ring groove, leading to jamming or breakage, affecting the assembly process and yield rate.
Design a piston installation tool including an upper guide sleeve and a lower guide sleeve. A tapered guide hole section is connected to a cylindrical through hole. An operating window is provided to facilitate piston ring adjustment and reset, reduce the tool height, and prevent the piston ring from coming off.
It reduces tool height and production costs, improves the yield rate of piston assemblies and production line efficiency, prevents piston ring jamming or breakage, and ensures smooth installation.
Smart Images
Figure CN224274919U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of engine technology, and in particular to a piston mounting tool. Background Technology
[0002] The piston installation tool is a specialized piece of equipment that uses a flared guide structure to precisely insert the piston assembly into the cylinder liner. The piston assembly consists of a piston body and pre-installed piston rings in the ring grooves. The piston rings are placed in the corresponding ring grooves in a semi-floating state, and the final press-fit positioning has not yet been completed.
[0003] Traditional piston installation tools have significant technical drawbacks: Firstly, to avoid the risk of breakage during piston ring press-fitting, the axial height of the tool must be increased to reduce the taper of the guide surface. This not only results in a large tooling size but also increases production costs. Secondly, when the piston ring does not retract sufficiently and detaches from the ring groove, the lack of a real-time monitoring mechanism makes it difficult for operators to detect such hidden faults in a timely manner. Uncorrected misaligned piston rings are highly likely to cause jamming or even breakage during subsequent assembly, hindering the smooth placement of the piston assembly, leading to assembly process interruptions, increased rework rates, and ultimately reduced production line efficiency and assembly yield. Utility Model Content
[0004] In view of this, the technical problem to be solved by this utility model is to provide a piston installation tool that can reduce the tool height and reduce production costs while meeting the piston assembly installation requirements; at the same time, it can adjust and reset the piston rings to prevent the piston rings from coming out of the ring groove and improve the yield rate.
[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:
[0006] A piston installation tool for installing a piston assembly into a cylinder liner, comprising an upper guide sleeve and a lower guide sleeve coaxially disposed below it;
[0007] The upper guide sleeve is provided with an upper through hole that extends through both ends along its axial direction. The upper through hole includes at least two guide hole segments that are connected end to end along the axial direction. The guide hole segments are conical. The lower guide sleeve is provided with a lower through hole that extends through both ends along its axial direction. The lower through hole is cylindrical. The guide hole segment located below is connected to the lower through hole.
[0008] An operation window is provided on the upper guide sleeve, and the operation window is connected to the upper through hole. The lower end of the operation window is not higher than the connection between the guide hole section and the lower through hole.
[0009] Preferably, the transition angle between two adjacent guide hole segments is defined as α, and the transition angle between the lower guide hole segment and the lower through hole is equal to α.
[0010] Preferably, the transition angle α between two adjacent guide hole sections is 3° to 5°.
[0011] Preferably, the inner diameter of the large-diameter end of the upper through hole is larger than the outer diameter of the piston ring in the free state.
[0012] Preferably, the inner diameter of the small-diameter end of the upper through hole, the inner diameter of the lower through hole, and the inner diameter of the cylinder liner are all equal.
[0013] Preferably, the inner diameter of the upper through hole corresponding to the upper end of the operation window is defined as R, and R is smaller than the inner diameter of the large diameter end of the upper through hole;
[0014] Define the piston diameter plus twice the width of the piston ring cross-section as r, where R is greater than r.
[0015] Preferably, the outer diameter of the lower guide sleeve is smaller than the outer diameter of the upper guide sleeve.
[0016] Preferably, the outer diameter of the lower guide sleeve is equal to the outer diameter of the carbon scraping ring.
[0017] Preferably, the outer wall of the upper guide sleeve is configured as a polyhedral structure formed by connecting multiple rectangular surfaces end to end, and the operation window is opened on one of the rectangular surfaces.
[0018] Preferably, the number of rectangular faces is eight.
[0019] After adopting the above technical solution, the beneficial effects of this utility model are:
[0020] The piston installation tool of this application includes an upper guide sleeve and a lower guide sleeve coaxially disposed below it. The upper guide sleeve has an upper through hole extending through both ends along its axial direction, and the upper through hole includes at least two axially connected guide hole segments, which are tapered. The lower guide sleeve has a lower through hole extending through both ends along its axial direction, and the lower through hole is cylindrical. The lower guide hole segment is connected to the lower through hole. During the installation of the piston assembly into the cylinder liner, the tapered guide hole segments can shrink the piston rings to fit into the corresponding ring grooves, meeting the installation requirements. By setting at least two guide hole segments, the angle difference between adjacent guide transition positions is reduced, ensuring a small transition angle and preventing the piston rings from shrinking too quickly due to an excessively large transition angle, which could lead to piston ring breakage. At the same time, the overall height of the tool is reduced, thus reducing production costs.
[0021] An operating window is provided on the upper guide sleeve, which communicates with the upper through hole. The lower end of the operating window is no higher than the connection between the guide hole section and the lower through hole. During the installation of the piston assembly into the cylinder liner, the piston rings that have come out of the ring groove during the descent can be reset, and the piston rings can be manually tightened at the transition position to prevent them from getting stuck or breaking, allowing the piston assembly to fall smoothly into the cylinder liner. In particular, the lower end of the operating window is no higher than the connection between the guide hole section and the lower through hole, which meets the need for manual tightening of the piston rings at the transition position and ensures that the piston rings fall normally into the lower through hole, allowing the piston assembly to be smoothly positioned, improving yield and production line efficiency. Attached Figure Description
[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0023] Figure 1 This is a schematic diagram of the piston installation tool according to an embodiment of the present invention;
[0024] Figure 2 yes Figure 1 A sectional view;
[0025] Figure 3 yes Figure 2 Enlarged view of part A;
[0026] Figure 4 yes Figure 2 The diagram shows the structure of the piston installation tool used to install the piston assembly onto the cylinder liner.
[0027] In the picture:
[0028] 1. Upper guide sleeve; 11. Upper through hole; 111. Guide hole section; 12. Operating window; 13. Rectangular surface;
[0029] 2. Lower guide sleeve; 21. Lower through hole;
[0030] 3. Piston assembly;
[0031] 4. Cylinder liner;
[0032] 5. Body. Detailed Implementation
[0033] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0034] like Figures 1 to 4As shown in the diagram, the piston installation tool disclosed in this utility model is used to install a piston assembly 3 into a cylinder liner 4. The piston installation tool includes an upper guide sleeve 1 and a lower guide sleeve 2 coaxially disposed below it. Preferably, the upper guide sleeve 1 and the lower guide sleeve 2 are integrally formed.
[0035] The upper guide sleeve 1 is provided with an upper through hole 11 that extends through both ends along its axial direction. The upper through hole 11 includes at least two guide hole segments 111 that are connected end to end along the axial direction. The guide hole segments 111 are tapered. The lower guide sleeve 2 is provided with a lower through hole 21 that extends through both ends along its axial direction. The lower through hole 21 is cylindrical. The guide hole segment 111 located below is connected to the lower through hole 21.
[0036] The cylinder liner 4 is pre-installed on the machine body 5. During the installation of the piston assembly 3 into the cylinder liner 4, the tapered guide hole section 111 can retract the piston rings to engage them in the corresponding ring grooves, meeting the installation requirements. By setting at least two guide hole sections 111, the angle difference between adjacent guide transition positions is reduced, ensuring a smaller transition angle. This prevents the piston rings from retracting too quickly due to an excessively large transition angle, which could lead to piston ring breakage. At the same time, it reduces the overall height of the tool and lowers production costs.
[0037] In this application, the transition angle between two adjacent guide hole segments 111 is defined as α, and the transition angle between the lower guide hole segment 111 and the lower through hole 21 is also equal to α. That is, the transition angle between two adjacent guide hole segments 111 and the transition angle between the lower guide hole segment 111 and the lower through hole 21 are equal, both being α. The transition angle α between two adjacent guide hole segments 111 is 3° to 5°, which reduces the angle α, thereby preventing the piston ring from shrinking too quickly due to an excessively large transition angle.
[0038] When installing the piston assembly 3, the piston assembly 3 passes through the upper through hole 11 and the lower through hole 21. Therefore, the piston ring on the piston assembly 3 first contacts the upper guide hole section 111 and the piston ring is contracted by the tapered guide hole section 111.
[0039] The inner diameter of the large-diameter end of the upper through hole 11 is larger than the outer diameter of the piston ring in the free state. Therefore, it can be ensured that the piston ring in the free state can be installed in the upper through hole 11 to meet the installation requirements.
[0040] Preferably, the inner diameter of the small diameter end of the upper through hole 11, the inner diameter of the lower through hole 21, and the inner diameter of the cylinder liner 4 are equal. After the piston ring is contracted into the ring groove, the piston ring is located in the lower through hole 21. At this time, the degree of contraction of the piston ring is limited by the inner diameter of the lower through hole 21, and its degree of contraction is consistent with the degree of contraction of the piston ring in the cylinder liner 4. This facilitates the piston ring to enter the interior of the cylinder liner 4 through the lower through hole 21 without affecting the installation of the piston assembly or causing excessive contraction of the piston ring.
[0041] An operating window 12 is provided on the upper guide sleeve 1, which communicates with the upper through hole 11. The lower end of the operating window 12 is not higher than the connection between the guide hole section 111 and the lower through hole 21. During the installation of the piston assembly 3 into the cylinder liner 4, the piston rings that have come out of the ring groove during the falling process can be reset. Furthermore, the piston rings can be manually tightened at the transition position (the transition position here refers to the connection between the lower guide hole section 111 and the lower through hole 21) to prevent the piston rings from getting stuck or breaking at the transition position, allowing the piston assembly 3 to fall smoothly into the cylinder liner 4. In particular, the lower end of the operating window 12 is not higher than the connection between the guide hole section 111 and the lower through hole 21, which meets the need for manual tightening of the piston rings at the transition position. Moreover, it ensures that the piston rings fall normally into the lower through hole 21, allowing the piston assembly 3 to fall smoothly into place, improving the yield rate and production line efficiency.
[0042] In this application, the inner diameter of the upper through hole 11 corresponding to the upper end of the operation window 12 is defined as R, and R is smaller than the inner diameter of the large diameter end of the upper through hole 11; the diameter of the piston plus twice the width of the piston ring cross section is defined as r, and R is greater than r.
[0043] During the process of piston assembly 3 entering the upper through hole 11, the piston ring is in a free state. From the moment the piston ring enters the upper through hole 11 until the piston ring reaches the height position corresponding to the inner diameter of the hole r, the piston ring does not compress inward enough during this falling height. There is a risk that the piston ring will come out of the piston ring groove. By setting the inner diameter R of the upper through hole 11 corresponding to the upper end of the operating window 12 to be greater than r, it is possible to ensure that the piston ring with the risk of coming out of the groove can be adjusted and repaired in time, and manual reset can be achieved.
[0044] The outer diameter of the lower guide sleeve 2 is smaller than the outer diameter of the upper guide sleeve 1; preferably, the height of the lower guide sleeve 2 is equal to the depth of the carbon scraping ring, and the outer diameter of the lower guide sleeve 2 is equal to the outer diameter of the carbon scraping ring, so that the lower guide sleeve 2 can be installed at the carbon scraping ring position of the cylinder liner 4.
[0045] In this application, to effectively prevent the inner bore from becoming out of round due to deformation of the piston installation tool, and to facilitate processing and use, the outer wall of the upper guide sleeve 1 is configured as a polyhedral structure formed by multiple rectangular surfaces 13 connected end to end, with the operating window 12 located on one of the rectangular surfaces 13; preferably, the number of rectangular surfaces 13 is eight. Slight out-of-roundness of the inner bore of the piston installation tool can lead to difficulties in the lifting process of the piston assembly 3, piston ring jamming or breakage, and piston surface abrasion; in cases of severe out-of-roundness, the piston installation tool may be rendered unusable. By configuring this application with an inner circle and outer square structure, the problem of large deformation in traditional annular structures is effectively avoided, which is beneficial for the processing and use of the piston installation tool.
[0046] When using the piston installation tool of this application, the piston assembly 3 is hoisted into the upper through hole 11, ensuring that the piston ring opening faces the operating window 12. The piston assembly 3 is then lowered, and during this descent, the piston rings are gradually compressed into the ring grooves. If any ring rings come out of the grooves, they are tightened through the operating window 12. After the piston assembly 3 is continuously lowered, it passes through the lower through hole 21 into the cylinder liner 4, completing the installation of the piston assembly 3.
[0047] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A piston installation tool for installing a piston assembly (3) into a cylinder liner (4), characterized in that, It includes an upper guide sleeve (1) and a lower guide sleeve (2) coaxially disposed below it; The upper guide sleeve (1) is provided with an upper through hole (11) extending through both ends along its axial direction. The upper through hole (11) includes at least two guide hole segments (111) connected end to end along the axial direction. The guide hole segments (111) are conical. The lower guide sleeve (2) is provided with a lower through hole (21) extending through both ends along its axial direction. The lower through hole (21) is cylindrical. The guide hole segment (111) located below is connected to the lower through hole (21). An operation window (12) is provided on the upper guide sleeve (1). The operation window (12) is connected to the upper through hole (11). The lower end of the operation window (12) is not higher than the connection between the guide hole section (111) and the lower through hole (21).
2. The piston installation tool as described in claim 1, characterized in that, The transition angle between two adjacent guide hole segments (111) is defined as α, and the transition angle between the lower guide hole segment (111) and the lower through hole (21) is equal to α.
3. The piston installation tool as described in claim 2, characterized in that, The transition angle α between two adjacent guide hole segments (111) is 3° to 5°.
4. The piston installation tool as described in claim 1, characterized in that, The inner diameter of the large-diameter end of the upper through hole (11) is larger than the outer diameter of the piston ring in the free state.
5. The piston installation tool as described in claim 4, characterized in that, The inner diameter of the small diameter end of the upper through hole (11), the inner diameter of the lower through hole (21), and the inner diameter of the cylinder liner (4) are all equal.
6. The piston installation tool as described in claim 4, characterized in that, The inner diameter of the upper through hole (11) corresponding to the upper end of the operation window (12) is defined as R, and R is smaller than the inner diameter of the large diameter end of the upper through hole (11). Define the piston diameter plus twice the width of the piston ring cross-section as r, where R is greater than r.
7. The piston installation tool as described in claim 1, characterized in that, The outer diameter of the lower guide sleeve (2) is smaller than the outer diameter of the upper guide sleeve (1).
8. The piston installation tool as described in claim 7, characterized in that, The outer diameter of the lower guide sleeve (2) is equal to the outer diameter of the carbon scraper ring.
9. The piston installation tool as described in claim 1, characterized in that, The outer wall of the upper guide sleeve (1) is configured as a polyhedral structure formed by connecting multiple rectangular surfaces (13) end to end, and the operation window (12) is opened on one of the rectangular surfaces (13).
10. The piston installation tool as described in claim 9, characterized in that, The number of rectangular faces (13) is eight.