Cast aluminum alloy piston capable of improving dimensional stability

Abstract

The cast aluminum alloy piston capable of improving the dimensional stability comprises a sealing ring groove formed in the top of the piston and a piston pin hole transversely penetrating through the piston, a plurality of cooling ring grooves are evenly formed in the outer wall, below the sealing ring groove, of the piston, and a guide groove is formed in the inner wall of the piston. A plurality of cooling vertical grooves are formed in the positions, corresponding to the piston pin holes, of the inner wall and the outer wall of the piston, and the cooling annular grooves, the guide grooves and the cooling vertical grooves can improve the surface area of the inner wall and the outer wall of the piston. And a plurality of guide-in holes are formed in the bottom of the piston, a plurality of heat dissipation holes are evenly formed in the top of the piston, and the heat dissipation holes are formed in the sealing ring groove, so that air entering the piston from the guide-in holes is exhausted from the heat dissipation holes after passing through the guide groove, and air circulation in the piston is achieved. The problems that in the prior art, due to the fact that the cooling speed is low in the machining cooling process of a piston, the grain structure in a piston material is thick, and the size stability of the piston is affected are solved.

Description

Technical Field

[0001] This utility model relates to the field of engine manufacturing technology, specifically to a cast aluminum alloy piston that can improve dimensional stability. Background Technology

[0002] In piston casting, the cooling process after pouring is a crucial step, as its rate has a significant and complex impact on the solidification process and final microstructure of the alloy. From the perspective of alloy solidification principles, the cooling rate directly determines the degree of supercooling during the transition from liquid to solid state. A faster cooling rate significantly increases the supercooling of the alloy, which greatly accelerates the formation rate of crystal nuclei during solidification. Due to the increased number of crystal nuclei, grain growth is mutually constrained within a limited space, ultimately resulting in smaller grain sizes. Refined grain structure is crucial for improving workpiece performance. Specifically, in terms of dimensional stability, smaller grains mean a greater number of grain boundaries. Grain boundaries, as interfaces between grains, possess high energy and irregular atomic arrangement. When the workpiece is affected by external factors, grain boundaries effectively hinder dislocation movement, thereby suppressing grain deformation and growth. This hindering effect allows the workpiece to better maintain its original dimensions during use, greatly improving its dimensional stability.

[0003] In most pistons today, the cooling process during casting is generally slow, which often results in coarse grain structure inside the piston material, thus affecting the dimensional stability of the piston. Utility Model Content

[0004] The purpose of this invention is to solve the problem in the prior art that the slow cooling rate of pistons during the processing and cooling process leads to coarse grain structure inside the piston material, which affects the dimensional stability of the piston, and to provide a cast aluminum alloy piston that can improve dimensional stability.

[0005] To address the shortcomings of the aforementioned technical problems, the present invention adopts the following technical solution: a cast aluminum alloy piston that can improve dimensional stability, comprising a sealing ring groove at the top of the piston and a piston pin hole that extends transversely through the piston. The piston has multiple cooling ring grooves evenly distributed on its outer wall below the sealing ring groove, and a guide groove is provided on the inner wall of the piston. The guide groove and the multiple cooling ring grooves are spaced apart from the piston pin hole. Multiple cooling vertical grooves are provided on both the inner and outer walls of the piston corresponding to the piston pin hole. The cooling ring grooves, guide grooves, and cooling vertical grooves can increase the surface area of ​​the inner and outer walls of the piston.

[0006] The piston has multiple inlet holes at its bottom and multiple heat dissipation holes evenly distributed at its top. The heat dissipation holes are located in the sealing ring groove so that air entering the piston from the inlet holes can be discharged through the heat dissipation holes after passing through the guide groove, thereby realizing air circulation inside the piston.

[0007] As a further optimization of the cast aluminum alloy piston of this utility model that can improve dimensional stability: the inlet hole is inclined, and the inclination direction of multiple inlet holes is consistent.

[0008] As a further optimization of the cast aluminum alloy piston of this utility model that can improve dimensional stability: the guide groove is spirally arranged.

[0009] As a further optimization of the present invention, which can improve the dimensional stability of a cast aluminum alloy piston: the piston is formed by casting high-damping alloy particles and aluminum alloy.

[0010] As a further optimization of the cast aluminum alloy piston of this utility model that can improve dimensional stability: the high damping alloy includes nickel-titanium based, copper-based or iron-based alloys.

[0011] As a further optimization of the cast aluminum alloy piston of this utility model that can improve dimensional stability: the minimum inner diameter of the cooling ring groove is larger than the outer edge of the outer cooling vertical groove, and the maximum inner diameter of the guide groove is larger than the inner edge of the inner cooling vertical groove.

[0012] As a further optimization of the cast aluminum alloy piston of this utility model that can improve dimensional stability: all the edges of the piston are rounded.

[0013] As a further optimization of the cast aluminum alloy piston of this utility model that can improve dimensional stability: multiple cooling vertical grooves are arranged along the piston axis, and multiple cooling vertical grooves are evenly distributed on the inner and outer walls of the piston.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This invention increases the surface area of ​​the piston's inner and outer walls by setting cooling ring grooves, cooling vertical grooves, and guide grooves. At the same time, it combines an inlet hole at the bottom of the piston and a heat dissipation hole at the top of the piston corresponding to the sealing ring groove to create air circulation inside the piston. Furthermore, the use of a blower can further increase the air circulation speed, thereby increasing the cooling speed of the piston's inner and outer walls during the cooling process. This improves the fineness of the internal grain composition of the piston material, thus solving to some extent the problem of coarse grain structure affecting the dimensional stability of the piston.

[0016] Furthermore, this invention uses high-damping alloy particles and aluminum alloy casting to make the piston. The high-damping alloy includes nickel-titanium based, copper-based and iron-based alloys, which improves the dimensional stability and wear resistance of the piston, while also increasing the mechanical strength of the piston.

[0017] Furthermore, this invention uses a spiral guide groove to work with a corresponding blower, so that the airflow enters the piston steadily from the inlet hole. Under the guidance of the spiral guide groove, the airflow spirals upward, so as to stably and evenly cool the inner wall of the piston. Finally, the airflow is discharged through the heat dissipation hole to complete the air circulation and achieve cooling of the piston interior. Attached Figure Description

[0018] Figure 1 This is a front view structural diagram of the present utility model;

[0019] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0020] The markings in the diagram are: 1. Piston; 2. Sealing ring groove; 3. Cooling ring groove; 4. Cooling vertical groove; 5. Piston pin hole; 6. Inlet hole; 7. Guide groove; 8. Heat dissipation hole. Detailed Implementation

[0021] To better understand this utility model, the following embodiments further illustrate the content of this utility model, but the content of this utility model is not limited to the following embodiments.

[0022] like Figure 1 As shown, a cast aluminum alloy piston with improved dimensional stability, similar to existing technologies, has a piston 1 with a sealing ring groove 2 on its top. Specifically, before the piston 1 is assembled into the cylinder for use, the sealing ring groove 2 can be connected to a corresponding sealing ring to seal the sealing ring groove 2, accommodating the gap between the piston 1 and the cylinder caused by dimensional tolerances, so that the piston 1 and the cylinder can be sealed together for use. A piston pin hole 5 is provided on the lower part of the outer circumference of the piston 1, extending laterally through the piston 1. Specifically, during use, the piston pin hole 5 can be connected to the connecting rod through the piston pin, and then the up and down movement of the piston 1 drives the crankshaft connected to the other end of the connecting rod to rotate, that is, the engine with the cylinder as the main support structure operates.

[0023] like Figure 1 and Figure 2As shown, unlike existing technologies, a cooling ring groove 3 is provided on the outer circumference of the piston 1 at the piston pin hole 5, and the cooling ring groove 3 is located below the sealing ring groove 2. Cooling vertical grooves 4 are provided on both the inner and outer walls of the piston 1 corresponding to the piston pin hole 5. The cooling vertical grooves 4 are arranged along the axial direction of the piston 1, thereby enhancing the axial load-bearing capacity of the piston 1 at the piston pin hole 5. This ensures the stability of the connection between the piston 1 and the connecting rod when the piston 1 moves within the cylinder and drives the piston pin and connecting rod. The cooling ring groove 3 and the cooling vertical groove 4 further enhance the piston's axial load-bearing capacity. 1. A surface structure resembling heat dissipation fins is formed, which increases the surface area of ​​piston 1, thereby increasing the contact area between the outer circumference of piston 1 and the air. This, in turn, increases the cooling rate of the outer circumference of piston 1 during the cooling process. Multiple inlet holes 6 are evenly distributed at the bottom of piston 1, and multiple heat dissipation holes 8 are evenly distributed on the sealing ring groove 2. When piston 1 is in use, the heat dissipation holes 8 can be sealed by a sealing ring that works in conjunction with the sealing ring groove 2, ensuring a sealed connection between piston 1 and cylinder. Furthermore, during the cooling process of piston 1 during manufacturing, the piston... The hot air inside piston 1 will dissipate through the heat dissipation hole 8, while the inlet hole 6 at the bottom of piston 1 allows cold air to enter, be heated and rise, so that a relatively fast air circulation is formed inside piston 1. At the same time, the cooling vertical groove 4 and guide groove 7 opened on the inner wall of piston 1 increase the surface area of ​​the inner wall of piston 1, which will increase the cooling rate inside piston 1. Then, with the cooling ring groove 3 and cooling vertical groove 4, the piston 1 can be cooled more synchronously and efficiently, thereby reducing the stress concentration on piston 1 to a certain extent. At the same time, the auxiliary efficient cooling can refine the grain structure inside piston 1 material, thereby improving the dimensional stability of piston 1 after manufacturing. Specifically, piston 1 is made of high-damping alloy particles and aluminum alloy casting. High-damping alloys include nickel-titanium based, copper-based and iron-based alloys. Specifically, the aluminum alloy can also be aluminum-silicon alloy, and the silicon content in the aluminum-silicon alloy is 20wt%. The finished product is obtained by adding high-damping alloy particles to aluminum alloy slurry and then die casting. The manufacturing process is simple, with good dimensional stability and wear resistance, and high mechanical strength.

[0024] Multiple inlet holes 6 are inclined, and their inclination direction is clockwise or counterclockwise. The inner wall of the piston 1 has a guide groove 7, which is spirally shaped. The guide groove 7 increases the surface area of ​​the inner wall of the piston 1, thereby increasing the contact area between the inner wall of the piston 1 and the air, thus maintaining the cooling rate inside the piston 1. Simultaneously, the spiral shape of the guide groove 7, in conjunction with the inclined inlet holes 6, guides the cold air, causing it to rise spirally within the piston 1 and exit through the heat dissipation hole 8, thus improving cooling efficiency to a certain extent. The piston 1 has a high internal cooling rate and uniformity. It can be placed in a location with wind or within the airflow coverage of a blower or other ventilation equipment. This allows the airflow to be guided upwards in a spiral motion and then discharged through the heat dissipation holes 8, further improving the cooling rate of the piston 1. The piston 1 also has rounded corners to reduce stress concentration at the corners, which could lead to structural instability or damage. Maintaining a consistent cooling rate with the outer periphery of the piston 1 also further reduces stress concentration inside the piston 1.

[0025] The minimum inner diameter of the cooling ring groove 3 is larger than the outer edge of the outer cooling vertical groove 4, so that the air passing through the cooling ring groove 3 can completely cover the outer cooling vertical groove 4 to maintain stable cooling of the outer surface of the piston 1. The maximum inner diameter of the guide groove 7 is larger than the inner edge of the inner cooling vertical groove 4, so that the guide groove 7 guides the air to pass stably through the multiple internal cooling vertical grooves 4 to maintain the cooling effect inside the piston 1.

[0026] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this utility model.

Claims

1. A cast aluminum alloy piston capable of improved dimensional stability comprising a seal ring groove (2) provided at the top of the piston (1) and a piston pin bore (5) extending transversely through the piston (1), characterized in that: The outer wall of the piston (1) below the sealing ring groove (2) is uniformly provided with a plurality of cooling ring grooves (3), the inner wall of the piston (1) is provided with a guide groove (7), the guide groove (7) and the plurality of cooling ring grooves (3) are arranged at intervals of the piston pin hole (5), the inner and outer walls of the piston (1) are provided with a plurality of cooling vertical grooves (4) corresponding to the piston pin hole (5), the cooling ring groove (3), the guide groove (7) and the cooling vertical groove (4) can increase the surface area of the inner and outer walls of the piston (1); The bottom of the piston (1) is provided with a plurality of inlet holes (6), and the top of the piston (1) is uniformly provided with a plurality of heat dissipation holes (8), the heat dissipation holes (8) are arranged in the sealing ring groove (2), so that the air entering the piston (1) from the inlet hole (6) is discharged from the heat dissipation hole (8) after passing through the guide groove (7), to realize the air circulation in the piston (1).

2. The cast aluminum alloy piston capable of improving dimensional stability according to claim 1, characterized by: The inlet hole (6) is inclined, and the inclination directions of the plurality of inlet holes (6) are consistent.

3. The cast aluminum alloy piston capable of improving dimensional stability according to claim 1, characterized by: The guide groove (7) is spirally arranged.

4. The cast aluminum alloy piston capable of improving dimensional stability according to claim 1, characterized by: The piston (1) is cast formed by high-damping alloy particles and aluminum alloy.

5. The cast aluminum alloy piston capable of improving dimensional stability according to claim 4, characterized by: The high-damping alloy includes nickel-titanium-based, copper-based or iron-based alloy.

6. The cast aluminum alloy piston capable of improving dimensional stability according to claim 1, characterized by: The minimum inner diameter of the cooling ring groove (3) is greater than the outer edge of the outer cooling vertical groove (4), and the maximum inner diameter of the guide groove (7) is greater than the inner edge of the inner cooling vertical groove (4).

7. The cast aluminum alloy piston capable of improving dimensional stability according to claim 1, characterized by: The corners of the piston (1) are all arranged with rounded corners.

8. The cast aluminum alloy piston capable of improving dimensional stability according to claim 1, characterized by: The plurality of cooling vertical grooves (4) are arranged along the axial direction of the piston (1), and the plurality of cooling vertical grooves (4) are uniformly distributed on the inner and outer walls of the piston (1).

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