Piston pin and engine

Abstract

The piston pin comprises a pin body and a core body, the pin body is provided with a cylindrical inner cavity in a penetrating mode, the inner cavity and the pin body are coaxially arranged, the two ends of the pin body are respectively provided with a first end face, and the range of the ratio of the inner diameter of the inner cavity to the outer diameter of the pin body is 0.9-0.95. The core body is cylindrical and arranged in the pin body, the circumferential outer side wall of the core body is matched with the circumferential inner side wall of the inner cavity, the two ends of the core body are provided with second end faces respectively, the second end faces are flush with the first end faces on the corresponding sides, and the core body is made of materials with the density lower than that of the pin body. The pin body is designed to be of a thin-wall structure, the inner cavity of the pin body is filled with the core body, the pin body bears main mechanical loads, and the overall performance of the core body is improved through stress dispersion and heat conduction enhancement. Due to the fact that the two second end faces of the core body are flush with the two first end faces of the pin body respectively, the inner cavity is completely filled with the core body, and the bearing capacity of the pin body of the thin-wall structure is improved.

Description

Technical Field

[0001] This utility model relates to the field of piston pin technology, specifically to a piston pin and an engine. Background Technology

[0002] As a key connecting component between the piston and connecting rod, the piston pin plays a crucial role in transmitting the combustion chamber load and coordinating reciprocating motion. However, traditional piston pins are generally made of a single metal material (such as 20CrMo alloy steel) and are thick-walled hollow structures. Although they have high strength, they have the following significant drawbacks: (1) Excessive weight. For example, the traditional thick-walled hollow structure of a gasoline engine (outer diameter 20mm, inner diameter 13mm, length 62mm) weighs 88g, accounting for about 20% of the total mass of the piston assembly, which leads to an increase in reciprocating inertial force; (2) Risk of stress concentration. The contact area of ​​the thick-walled hollow structure is a stress concentration area. Local stress concentration can easily lead to fatigue cracks and reduce service life. Based on this, a piston pin that balances lightweight and high fatigue strength is proposed. Utility Model Content

[0003] In view of the deficiencies in the prior art, the purpose of this utility model is to provide a piston pin and engine that can balance lightweight and high fatigue strength.

[0004] To achieve the above objectives, this utility model provides a piston pin, comprising a pin body having a cylindrical inner cavity extending through it, the inner cavity being coaxially arranged with the pin body, the pin body having a first end face at each end, and the ratio of the inner diameter of the inner cavity to the outer diameter of the pin body ranging from 0.9 to 0.95; and a cylindrical core disposed within the pin body, the outer circumferential wall of the core engaging with the inner circumferential wall of the inner cavity, the core having a second end face at each end, the second end face being flush with the first end face on the corresponding side, and the core being made of a material with a lower density than the pin body.

[0005] Preferably, the core is a solid structure.

[0006] Preferably, the core is made of aluminum alloy.

[0007] Preferably, the pin is made of high-strength alloy steel.

[0008] Preferably, the wall thickness of the pin is 0.5 to 1.0 mm.

[0009] Preferably, the diameter of the core is 18-19 mm.

[0010] This utility model also provides an engine, including the piston pin described above.

[0011] The beneficial effects of this utility model are:

[0012] This utility model discloses a piston pin and an engine. The pin is designed with a thin-walled structure, and a core is filled inside the pin's cavity. The pin bears the main mechanical load, while the core enhances overall performance through stress dispersion and thermal conductivity. Since the two second end faces of the core are flush with the two first end faces of the pin, the core completely fills the cavity, thereby improving the load-bearing capacity of the thin-walled pin. Furthermore, because the core is made of a material with a lower density than the pin, combined with the thin-walled structure, the piston pin of this application is lighter than conventional thick-walled hollow piston pins, resulting in less reciprocating inertial force during operation and improved engine efficiency. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0014] Figure 1 A cross-sectional schematic diagram of a piston pin provided in an embodiment of the present invention;

[0015] Figure 2 This is a cross-sectional schematic diagram of the pin.

[0016] Figure 3 Stress analysis diagram of piston pin in traditional thick-walled hollow structure;

[0017] Figure 4 This is a stress analysis diagram of the piston pin in this application;

[0018] Figure label:

[0019] 10. Pin; 11. Inner cavity; 12. First end face; 20. Core; 21. Second end face. Detailed Implementation

[0020] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0021] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

[0022] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0023] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly defined.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] like Figure 1-4 As shown, in one embodiment of this utility model, a piston pin is provided, including a pin body 10 and a core 20. The pin body 10 has a cylindrical inner cavity 11 extending through it. The inner cavity 11 is coaxially arranged with the pin body 10, and each end of the pin body 10 has a first end face 12. The ratio of the inner diameter of the inner cavity 11 to the outer diameter of the pin body 10 is in the range of 0.9 to 0.95, thus making the pin body 10 a thin-walled structure.

[0027] The core 20 is cylindrical and is disposed within the pin 10. The core 20 is assembled into the inner cavity 11 by pressing or otherwise. The outer circumferential wall of the core 20 mates with the inner circumferential wall of the inner cavity 11. Each end of the core 20 has a second end face 21, which is flush with the first end face 12 on the corresponding side. The core 20 is made of a material with a lower density than the pin 10.

[0028] Specifically, the core 20 is a solid structure, made of AlSi12CuMg material, and the pin 10 is made of 20CrMo material.

[0029] A conventional thick-walled hollow piston pin made of 20CrMo material has the following dimensions: outer diameter 20mm, inner diameter 13mm, length 62mm, and weight 88g. The piston pin of this application, however, has a pin body 10 also made of 20CrMo material, with dimensions of 20mm outer diameter, 18mm inner diameter, 1mm wall thickness, and 62mm length; the core 20 is made of AlSi12CuMg material, with dimensions of 18mm outer diameter and 62mm length. The total weight of this piston pin is 72g, representing an 18% weight reduction compared to the conventional piston pin (88g).

[0030] See Figure 3 and Figure 4 The piston pins of the present application still use the two types of piston pins with the above-mentioned dimensions. Compared with the piston pins of the traditional thick-walled hollow structure, the maximum stress of the piston pins of this application is reduced by 4%.

[0031] By designing the pin 10 as a thin-walled structure and filling the inner cavity 11 of the pin 10 with a core 20, the pin 10 bears the main mechanical load, while the core 20 enhances overall performance through stress dispersion and thermal conductivity. Since the two second end faces 21 of the core 20 are flush with the two first end faces 12 of the pin 10, the core 20 completely fills the inner cavity 11, thereby improving the load-bearing capacity of the thin-walled pin 10. Simultaneously, because the core 20 is made of a material with a lower density than the pin 10, combined with the thin-walled structure of the pin 10, the piston pin of this application is lighter than that of a conventional thick-walled hollow piston pin, resulting in less reciprocating inertial force during operation and improved engine efficiency.

[0032] This embodiment also provides an engine including the piston pin described above. Because it uses the piston pin described above, it has the same working principle and technical effects as the piston pin in the above embodiments, and will not be repeated here.

[0033] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A piston pin, characterized in that, include: A pin (10) has a cylindrical inner cavity (11) extending through it. The inner cavity (11) is coaxially arranged with the pin (10). The two ends of the pin (10) each have a first end face (12). The ratio of the inner diameter of the inner cavity (11) to the outer diameter of the pin (10) is in the range of 0.9 to 0.

95. A cylindrical core (20) is disposed inside the pin (10). The outer circumferential wall of the core (20) is fitted with the inner circumferential wall of the inner cavity (11). The two ends of the core (20) are respectively provided with a second end face (21). The second end face (21) is flush with the first end face (12) on the corresponding side. The core (20) is made of a material with a lower density than the pin (10).

2. The piston pin according to claim 1, characterized in that, The core (20) is a solid structure.

3. The piston pin according to claim 1, characterized in that, The core (20) is made of aluminum alloy.

4. The piston pin according to claim 1, characterized in that, The pin (10) is made of high-strength alloy steel.

5. The piston pin according to claim 1, characterized in that, The wall thickness of the pin (10) is 0.5 to 1.0 mm.

6. The piston pin according to claim 1, characterized in that, The core (20) has a diameter of 18-19 mm.

7. An engine, characterized in that, Includes the piston pin according to any one of claims 1-6.

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