piston

Abstract

The utility model discloses a piston relates to piston technical field, wherein, piston includes piston main part and support structure, and piston main part includes head, two first skirts and two second skirts, and the head is cylindrical, and two first skirts are connected respectively in the lower side of the both sides of head along the transverse, and two second skirts are connected respectively in the lower side of the both sides of head along the longitudinal, and each second skirt is equipped with the pinhole that extends along the longitudinal, and the structural strength of support structure is greater than the structural strength of piston main part, and support structure includes head support, two skirt supports and two pinhole supports, and head support is embedded in the head, and two skirt supports are embedded respectively in two first skirts, and two pinhole supports are embedded respectively in two second skirts, and each pinhole extends along the longitudinal, and each pinhole support is ringed in the corresponding pinhole. Embed the support structure of higher structural strength in the inside of piston main part, both maintain the lightweight design of piston, and relieve the stress concentration in the piston.

Description

Technical Field

[0001] This utility model relates to the field of piston technology, and in particular to a piston. Background Technology

[0002] As a core component of an engine, the piston's structural strength and material usage significantly impact overall engine performance and cost. Currently, traditional pistons are typically manufactured using integral metal casting or forging. To ensure load-bearing capacity under high temperature and pressure conditions, it is often necessary to increase the wall thickness of key areas or use dense materials for overall reinforcement. However, while this approach improves piston rigidity and durability, it also leads to a significant increase in weight and a decrease in material utilization, resulting in unnecessary resource waste and increased costs. Furthermore, during long-term high-load operation, the piston skirt, especially the pin hole area, is prone to fatigue cracks or deformation due to stress concentration. Existing structures often employ an overall thickening design to compensate for insufficient local strength, further exacerbating redundant material usage and making it difficult to achieve a balance between lightweight and high strength. Utility Model Content

[0003] The main purpose of this invention is to propose a piston that aims to solve the technical problem that pistons in the prior art are difficult to balance between lightweight and high strength.

[0004] To achieve the above objectives, the piston proposed in this utility model includes a piston body and a support structure. The piston body includes a head, two first skirts, and two second skirts. The head is cylindrical. The two first skirts are respectively connected to the lower sides of the head along the lateral direction, and the two second skirts are respectively connected to the lower sides of the head along the longitudinal direction. Each second skirt has a pin hole extending longitudinally. The structural strength of the support structure is greater than that of the piston body. The support structure includes a head support, two skirt supports, and two pin hole supports. The head support is embedded in the head, the two skirt supports are respectively embedded in the two first skirts, and the two pin hole supports are respectively embedded in the two second skirts. Each pin hole extends longitudinally, and each pin hole support is circumferentially arranged around the corresponding pin hole.

[0005] In one embodiment, the head support includes a top wall and a side wall, the side wall being a vertically extending cylindrical shape, the top wall being connected to the upper end of the side wall, and each of the skirt supports being connected to the lower end of the side wall and extending downward.

[0006] In one embodiment, each of the skirt supports is in the shape of an arc-shaped plate, and the cross-section of each skirt support has the same curvature as the cross-section of the sidewall.

[0007] In one embodiment, the arc length of each of the skirt supports is gradually increased from top to bottom.

[0008] In one embodiment, the head support and the two skirt supports are integrally formed.

[0009] In one embodiment, the support structure is a prefabricated component, which is cast into the piston body.

[0010] In one embodiment, the top wall, the side wall, each of the skirt supports and each of the pin hole supports are provided with a plurality of through casting holes spaced apart.

[0011] In one embodiment, a plurality of casting holes formed on the top wall are evenly distributed at intervals along the edge of the top wall, a plurality of casting holes formed on the side wall and the two skirt supports are evenly distributed at intervals, and a plurality of casting holes formed on each of the pin hole supports are evenly distributed at intervals.

[0012] In one embodiment, the top wall is a planar circular wall, and the connection between the top wall and the side wall is chamfered.

[0013] In one embodiment, each of the pin hole supports has a non-closed annular structure, and the cross-section of the pin hole support along the circumferential direction is C-shaped.

[0014] The piston proposed in this utility model, by embedding a support structure with higher structural strength inside the piston body, precisely strengthens the high-load area inside the piston, avoiding the redundant use of materials caused by the overall thickening design of traditional piston reinforcement. This not only avoids material waste and maintains the overall lightweight design of the piston, but also effectively alleviates the stress concentration problem in the high-load area inside the piston, thus taking into account both structural strength and lightweight requirements. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 A schematic diagram of a piston embodiment provided by this utility model; Figure 2 A side view of an embodiment of the piston provided by this utility model; Figure 3 A schematic diagram of the piston support structure provided by this utility model from one perspective and one embodiment; Figure 4A schematic diagram of the piston support structure provided by this utility model from another perspective of one embodiment.

[0017] Explanation of icon numbers: 10. Piston body; 11. Head; 12. First skirt; 13. Second skirt; 131. Pin hole; 20. Support structure; 21. Head support; 211. Top wall; 212. Side wall; 22. Skirt support; 23. Pin hole support; 24. Casting hole.

[0018] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0020] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0022] In this utility model, the descriptions of directions such as "up", "down", "front", "back", "left", and "right" are as follows: Figure 1 The directions shown are for reference only and are used to interpret the location. Figure 1The relative positional relationship between the components in the shown posture is such that if the specific posture changes, the directional indication will also change accordingly.

[0023] Currently, traditional pistons are typically manufactured using integral metal casting or forging. To ensure load-bearing capacity under high temperature and high pressure conditions, it is often necessary to increase the wall thickness of key components or use dense materials for overall reinforcement. However, while this approach can improve the piston's rigidity and durability, it also leads to a significant increase in weight and a decrease in material utilization, resulting in unnecessary resource waste and increased costs. Furthermore, during long-term high-load operation, the piston skirt, especially the pin hole area, is prone to fatigue cracks or deformation due to stress concentration. Existing structures often opt for an overall thickening design to compensate for insufficient local strength, further exacerbating the redundant use of materials and making it difficult to achieve a balance between lightweight and high strength.

[0024] This utility model proposes a piston, including a piston body 10 and a support structure 20. The piston body 10 includes a head 11, two first skirts 12 and two second skirts 13. The head 11 is cylindrical. The two first skirts 12 are respectively connected to the lower sides of the head 11 in the transverse direction. The two second skirts 13 are respectively connected to the lower sides of the head 11 in the longitudinal direction. Each second skirt 13 has a pin hole 131 extending in the longitudinal direction. The structural strength of the support structure 20 is greater than that of the piston body 10. The support structure 20 includes a head support 21, two skirt supports 22 and two pin hole supports 23. The head support 21 is embedded in the head 11. The two skirt supports 22 are respectively embedded in the two first skirts 12. The two pin hole supports 23 are respectively embedded in the two second skirts 13. Each pin hole 131 extends in the longitudinal direction, and each pin hole support 23 is circumferentially arranged around the corresponding pin hole 131.

[0025] Please see Figure 1 and Figure 2 , Figure 1 The left and right directions in the middle are the horizontal directions. Figure 1 The front-to-back direction in the middle is the longitudinal direction. Figure 1The vertical direction is defined as the vertical direction. The head support 21 matches the cylindrical geometry of the head 11, allowing the head support 21 to be embedded within the head 11. This evenly distributes the high-pressure load on the piston head 11 and prevents localized deformation. The skirt support 22 matches the geometry of the first skirt 12, allowing each skirt support 22 to be embedded within its corresponding first skirt 12. The skirt support 22 is used to strengthen the lateral stiffness of the piston to resist lateral forces during piston movement and reduce skirt wear. The pin hole support 23 matches the geometry of the second skirt 13, allowing each pin hole support 23 to be embedded within its corresponding second skirt 13. This directly reinforces the stress concentration area of ​​the second skirt 13, effectively dispersing the alternating stress around the pin hole 131 and suppressing fatigue crack formation. The support structure 20 is embedded in the high-load area inside the piston body 10, and its structural strength is greater than that of the piston body 10. This allows the support structure 20 to act as a supporting skeleton within the piston body 10, providing localized structural strength reinforcement at its installation location. This ensures that the stress distribution at various points on the piston matches the structural strength, achieving targeted reinforcement in high-load areas and avoiding material redundancy caused by the overall thickening design of traditional pistons. It should be noted that the greater structural strength of the support structure 20 than that of the piston body 10 means that the yield strength of the material used to manufacture the support structure 20 is higher than that of the material used to manufacture the piston body 10. For example, the support structure 20 can be made of a nickel-based high-temperature alloy using powder metallurgy sintering, while the piston body 10 can be made of gravity-cast aluminum alloy. This provides additional load-bearing capacity in critical areas without increasing the overall mass.

[0026] The piston proposed in this utility model, by embedding a support structure 20 with higher structural strength inside the piston body 10, precisely strengthens the high-load area inside the piston. This avoids the redundant use of materials caused by the overall thickening design of traditional piston reinforcement, thus avoiding material waste, maintaining the overall lightweight design of the piston, and effectively alleviating the stress concentration problem in the high-load area inside the piston, thereby taking into account both structural strength and lightweight requirements.

[0027] In one embodiment, the head support 21 includes a top wall 211 and a side wall 212. The side wall 212 is a cylindrical shape that extends vertically. The top wall 211 is connected to the upper end of the side wall 212, and each skirt support 22 is connected to the lower end of the side wall 212 and extends downward.

[0028] Please continue reading. Figure 2The sidewall 212 being a vertically extending cylindrical shape means that the sidewall 212 has a cylindrical structure, which allows the sidewall 212 to form a tight fit interface with the piston head 11, ensuring uniform distribution of circumferential stress. Specifically, the top wall 211 being connected to the upper end of the sidewall 212 means that the top wall 211 closes the upper opening of the sidewall 212. It can be a flat surface or a slightly convex curved surface, which can form a continuous pressure-bearing surface to resist the high-pressure impact of the combustion chamber and avoid stress concentration at sharp corners. In addition, each skirt support 22 being connected to the lower end of the sidewall 212 and extending downward means that the skirt support 22 extends from the lower end of the sidewall 212 to the area of ​​the first skirt 12. It can be a straight plate or an arc plate, the purpose of which is to smoothly transfer the load of the head 11 to the skirt support 22 and avoid abrupt changes in stiffness at the junction of the head 11 and the skirt. The solution of this application forms a circumferentially fitted interface with the inner cavity of the piston head 11 through the cylindrical design of the side wall 212, effectively bridging the stress transmission discontinuity caused by abrupt shape changes in traditional structures and evenly distributing the combustion pressure to the entire head 11 area; the connection between the top wall 211 and the upper end of the side wall 212 forms a closed pressure-bearing surface, maximizing the pressure-bearing area while ensuring continuous deformation resistance in the transition area; the skirt support 22 is connected to the lower end of the side wall 212 based on the geometric continuity of the cylindrical shape of the side wall 212 and extends downward, smoothly transferring the load of the head 11 to the skirt support 22 through the side wall 212, so that the side wall 212 and the skirt support 22 form an integrated force flow channel, ensuring that the lateral and longitudinal loads are efficiently transmitted to the piston body 10 through the support system, thereby reducing material redundancy while strengthening the fatigue resistance of key connection areas.

[0029] In one embodiment, each skirt support 22 is in the shape of an arc plate, and the cross-section of each skirt support 22 is consistent with the curvature of the cross-section of the side wall 212.

[0030] It can be explained that the skirt support 22 being arc-shaped means that the skirt support 22 has a continuously curved plate-like structure, which allows the skirt support 22 to naturally conform to the curved contour of the cylindrical head 11 of the piston body 10, avoiding geometric discontinuities caused by abrupt changes in angle. The fact that the cross-section of each skirt support 22 has the same curvature as the cross-section of the side wall 212 ensures the geometric continuity of the connection interface between the skirt support 22 and the side wall 212, eliminating the small gaps or steps caused by differences in curvature in traditional designs, and forming a seamless transition of continuous curved surfaces at the connection between the skirt support 22 and the side wall 212 of the head support 21. When the piston bears the lateral load of the engine, the arc-shaped structure guides the stress to be evenly distributed along the curved surface, avoiding the stress peak caused by the geometric change of the straight plate support. At the same time, since the side wall 212 is a vertical cylindrical shape and the cross-section is a fixed arc, the skirt support 22 uses a cross-section with the same arc to ensure that the load is smoothly introduced from the side wall 212 to the skirt support 22, which significantly suppresses the stress concentration phenomenon in the connection area, thereby dispersing the local high stress area to the entire support structure 20.

[0031] In one embodiment, the arc length of each skirt support 22 is gradually increased from top to bottom.

[0032] Furthermore, the arc length of the skirt support 22 refers to the arc length of the cross-section at each height of the skirt support 22. Since the upper end of the first skirt 12 of the piston body 10 is connected to the head 11, and the head 11 provides support for the first skirt 12, the structural strength of the first skirt 12 gradually decreases as it moves further away from the head 11. By making the skirt support 22 gradually expand in arc length from top to bottom, the structural strength of the skirt support 22 itself gradually increases from top to bottom. This dynamically matches the structural strength of the skirt support 22 with the structural strength of the first skirt 12, resulting in a more uniform distribution of structural strength at each height in the structure formed after the skirt support 22 is embedded in the first skirt 12. The gradually expanding arc length of the skirt support 22 can form a continuous and uniform stress transmission path in the height direction, avoiding the generation of local stress concentration points.

[0033] In one embodiment, the head support 21 and the two skirt supports 22 are integrally formed.

[0034] Understandably, the head support 21 and the two skirt supports 22 are integrally formed. Specifically, they can be achieved by integral casting, powder metallurgy sintering or laser selective melting additive manufacturing processes in the existing technology. This avoids the physical connection interface that exists after the assembly of traditional split supports, and ensures that the load is smoothly transferred between the head 11 and the first skirt 12. The purpose is to eliminate stress concentration caused by micro gaps and improve the overall stiffness and fatigue strength of the support structure 20.

[0035] In one embodiment, the support structure 20 is a prefabricated component, which is cast into the piston body 10.

[0036] Understandably, the support structure 20 is prefabricated independently before the piston body 10 is manufactured. It can be made of high-strength alloy material through casting or powder metallurgy process, thereby avoiding the problem of thermal stress mismatch between the piston body 10 material and the support structure 20 during the casting process. In particular, during the casting process of the piston body 10, the prefabricated support structure 20 is embedded in the mold, so that the piston body 10 material forms a firm bond with the support structure 20 when it solidifies, reducing interface defects and stress concentration at the joint of the piston body 10 and the support structure 20.

[0037] In one embodiment, the top wall 211, side wall 212, each skirt support 22 and each pin hole support 23 are provided with a plurality of through casting holes 24 spaced apart.

[0038] It should be noted that during the casting process of the piston body 10, the casting holes 24 allow the molten metal to fully penetrate the interior of the support during the casting process, thereby reducing the gaps and pores at the bonding interface and further improving the connection stability between the support structure 20 and the piston body 10. The casting holes 24 are distributed at a certain interval on the support structure 20, ensuring sufficient penetration channels while maintaining the local strength of the support structure 20. The multiple holes distributed at intervals provide multiple flow paths, ensuring uniform filling of the molten metal, reducing the formation of pores and voids, thereby significantly improving the reliability and durability of the bonding interface between the support and the piston body 10.

[0039] In one embodiment, a plurality of casting holes 24 formed on the top wall 211 are evenly distributed at intervals along the edge of the top wall 211, a plurality of casting holes 24 formed on the side wall 212 and the two skirt supports 22 are evenly distributed at intervals, and a plurality of casting holes 24 formed on each pin hole support 23 are evenly distributed at intervals.

[0040] Understandably, by opening evenly spaced casting holes 24 at the edge of the top wall 211, molten metal flows in evenly along the top wall 211, enhancing the integrity of the top structure; by opening evenly distributed casting holes 24 in the side wall 212 and skirt support 22 areas, the material filling consistency of the lateral support area is ensured, reducing interface stress concentration; in addition, by opening evenly spaced casting holes 24 on the pin hole support 23, molten metal is filled evenly in the circumferential direction, effectively dispersing the concentrated stress at the pin hole 131, thereby improving the overall structural uniformity and reliability of the piston.

[0041] In one embodiment, the top wall 211 is a planar circular wall, and the connection between the top wall 211 and the side wall 212 is chamfered.

[0042] In practical applications, the top wall 211 refers to the upper surface load-bearing structure of the head support 21. Its circular planar design allows the load borne by the head 11 to be evenly distributed to the top wall 211, ensuring uniform stress distribution within the piston. The connection between the top wall 211 and the side wall 212 is chamfered, which can be achieved using rounded corners or beveled transitions. This aims to eliminate sharp edges formed by right-angle connections, reduce stress concentration at the connection between the top wall 211 and the side wall 212, and significantly improve the continuity and stability of stress transmission.

[0043] In one embodiment, each pin hole bracket 23 has a non-closed annular structure, and the cross-section of the pin hole bracket 23 along the circumferential direction is C-shaped.

[0044] It should be noted that the non-closed ring structure refers to the fact that the ring contour of the pin hole support 23 is not completely closed, leaving an opening gap, which can provide elastic space for stress release. This allows the pin hole support 23 to expand or contract elastically within a certain range along the circumference, avoiding the high stress concentration caused by the rigid constraint of the closed ring structure. At the same time, the C-shaped cross-section design allows the mechanical load to be smoothly dispersed along the circumference when under force, suppressing the crack propagation path, thereby effectively alleviating the interface stress caused by the difference in thermal expansion of materials, preventing the propagation of fatigue cracks, and improving the strengthening effect of the support structure 20.

[0045] The above description is merely an exemplary embodiment of the present utility model and does not limit the scope of protection of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present utility model.

Claims

1. A piston, characterized in that, include: The piston body includes a head, two first skirts and two second skirts. The head is cylindrical. The two first skirts are respectively connected to the lower sides of the head along the lateral direction. The two second skirts are respectively connected to the lower sides of the head along the longitudinal direction. Each second skirt has a pin hole extending longitudinally. The support structure has a structural strength greater than that of the piston body. The support structure includes a head support, two skirt supports, and two pin hole supports. The head support is embedded in the head, the two skirt supports are respectively embedded in the two first skirts, and the two pin hole supports are respectively embedded in the two second skirts. Each pin hole extends longitudinally, and each pin hole support is circumferentially disposed around the corresponding pin hole.

2. The piston as claimed in claim 1, characterized in that, The head support includes a top wall and side walls. The side walls are cylindrical and extend vertically. The top wall is connected to the upper end of the side walls, and each of the skirt supports is connected to the lower end of the side walls and extends downward.

3. The piston as described in claim 2, characterized in that, Each of the skirt supports is in the shape of an arc plate, and the cross-section of each skirt support has the same curvature as the cross-section of the side wall.

4. The piston as claimed in claim 3, characterized in that, The arc length of each skirt support gradually increases from top to bottom.

5. The piston as claimed in claim 3, characterized in that, The head support and the two skirt supports are integrally formed.

6. The piston as claimed in claim 2, characterized in that, The support structure is a prefabricated component, which is cast into the piston body.

7. The piston as claimed in claim 6, characterized in that, The top wall, the side wall, each of the skirt supports, and each of the pin hole supports are all provided with multiple through casting holes spaced apart.

8. The piston as claimed in claim 7, characterized in that, The plurality of casting holes formed on the top wall are evenly distributed at intervals along the edge of the top wall, the plurality of casting holes formed on the side wall and the two skirt supports are evenly distributed at intervals, and the plurality of casting holes formed on each of the pin hole supports are evenly distributed at intervals.

9. The piston as claimed in claim 2, characterized in that, The top wall is a planar circular wall, and the connection between the top wall and the side wall is chamfered.

10. The piston as claimed in any one of claims 1 to 9, characterized in that, Each of the pin hole supports has a non-closed annular structure, and the cross-section of the pin hole support along the circumferential direction is C-shaped.

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