Piston with steel-aluminum structure

Abstract

The invention discloses a piston with a steel-aluminum structure. The steel-aluminum structure piston comprises a piston upper body made of cast steel materials and of a bowl-shaped structure, and a combustion chamber is arranged on the inner surface of the piston upper body; the piston skirt part is made of an aluminum alloy material and is fixedly connected with the piston upper body; and the top surface of the piston skirt part is provided with a groove matched with the outer surface of the piston upper body. The steel-aluminum structure piston is made of two composite materials of cast steel and aluminum alloy, the piston upper body is made of the cast steel material, and the piston skirt is made of the aluminum alloy material. The piston upper body made of cast steel can be compatible with high-temperature combustion of a combustion chamber, thermal load capacity of the engine combustion chamber is improved, and the piston skirt made of aluminum alloy can reduce weight of the piston and motion inertia force of a piston connecting rod mechanism.

Description

Technical Field

[0001] The invention relates to the field of automobile engines, in particular to a steel-aluminum structure piston. Background Art

[0002] Among the existing engine pistons, aluminum alloy pistons are the most widely used pistons in engines. They have low density, light weight, good thermal conductivity, excellent molding performance, and easy surface treatment of the piston surface. They are used in gasoline engines or diesel engines with low combustion temperatures.

[0003] However, in heavy machinery or diesel engines that use coarse fuel, cast iron pistons or steel pistons are usually required to meet high-temperature combustion requirements, mainly because the piston head is required to have a higher temperature tolerance.

[0004] Existing aluminum alloy pistons, cast iron pistons or steel pistons also have the following defects:

[0005] Aluminum alloy pistons have disadvantages such as not being able to withstand high temperatures, having a large expansion coefficient, and being easy to wear. During high-temperature combustion in the engine combustion chamber, the top of the piston is prone to failures such as melting and ablation; due to the high expansion coefficient of aluminum alloy, the piston head will become stuck when it cooperates with the cylinder wall and piston ring in a high-temperature environment; aluminum alloy pistons are prone to wear in high-temperature and high-pressure environments, which will affect their service life and performance.

[0006] Cast iron pistons or steel pistons have disadvantages such as heavy weight, poor thermal conductivity, and difficulty in processing. The high density of iron and steel leads to a heavy piston weight, which increases the inertia force of the piston's reciprocating motion and affects the engine's response speed and fuel efficiency; the poor thermal conductivity of cast iron or steel is not conducive to engine heat dissipation, so a more powerful cooling system is needed to ensure the normal operation of the engine; iron and steel are difficult to process, requiring higher manufacturing precision and more complex process flows.

[0007] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0008] The purpose of the present invention is to provide a steel-aluminum structure piston with a simple and reasonable structure, which can be compatible with high-temperature combustion in the combustion chamber, improve the heat load capacity of the engine combustion chamber, and at the same time reduce the weight of the piston and reduce the inertia force of the piston connecting rod mechanism.

[0009] To achieve the above-mentioned purpose, the present invention provides a steel-aluminum structure piston, including: a piston upper body, which is made of cast steel material, and the piston upper body is a bowl-shaped structure, and a combustion chamber is arranged on its inner surface; and a piston skirt, which is made of aluminum alloy material and is fixedly connected to the piston upper body; the top surface of the piston skirt has a groove adapted to the outer surface of the piston upper body.

[0010] In a preferred embodiment, the combustion chamber of the piston upper body is an ω-shaped combustion chamber.

[0011] In a preferred embodiment, the piston skirt further includes: an inner cooling oil channel, a piston ring groove and a piston pin hole.

[0012] In a preferred embodiment, the outer surface of the piston upper body is provided with a plurality of positioning bosses, and the top surface of the piston skirt is provided with a plurality of positioning holes matched with the positioning bosses.

[0013] In a preferred embodiment, the positioning bosses are evenly distributed along the circumference of the piston upper body, and the positioning holes are evenly distributed along the circumference of the piston skirt.

[0014] In a preferred embodiment, the outer surface of the piston upper body and the top surface of the piston skirt are mutually adapted to form an ω-shape.

[0015] Compared with the prior art, the steel-aluminum structure piston according to the present invention has the following beneficial effects: the steel-aluminum structure piston adopts two composite materials of cast steel and aluminum alloy, the piston upper body is cast steel material, and the piston skirt is aluminum alloy material. The cast steel material piston upper body can be compatible with high-temperature combustion in the combustion chamber, and improve the heat load capacity of the engine combustion chamber. At the same time, the aluminum alloy material piston skirt can reduce the weight of the piston and reduce the inertia force of the piston connecting rod mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the drawings required for use in the implementation methods will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of a steel-aluminum structure piston according to an embodiment of the present invention.

[0018] Figure 2 It is a schematic diagram of the exploded structure of a steel-aluminum structure piston according to one embodiment of the present invention.

[0019] Figure 3 It is a schematic cross-sectional view of a steel-aluminum structure piston according to an embodiment of the present invention.

[0020] Figure 4 It is a schematic diagram of the assembly cross-sectional structure of a steel-aluminum structure piston according to one embodiment of the present invention. DETAILED DESCRIPTION

[0021] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0022] In order to make the purpose, technical solutions and advantages of the implementation methods of this application clearer, the technical solutions in the implementation methods of this application will be clearly and completely described below in conjunction with the drawings in the implementation methods of this application. Obviously, the described implementation methods are part of the implementation methods of this application, not all of the implementation methods. Based on the implementation methods in this application, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0027] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0028] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0029] like Figures 1 to 4 As shown, the specific structure of the steel-aluminum structure piston according to the preferred embodiment of the present invention includes: a piston upper body 1, and a piston skirt 2 fixed below the piston upper body 1, wherein the piston upper body 1 is made of cast steel material and has an ω-shaped combustion chamber. The piston skirt 2 is made of aluminum alloy material. The piston upper body 1 and the piston skirt 2 of the steel-aluminum structure piston are respectively made of two composite materials, cast steel and aluminum alloy. The piston upper body made of cast steel can be compatible with high-temperature combustion in the combustion chamber and improve the heat load capacity of the engine combustion chamber. At the same time, the piston skirt made of aluminum alloy can reduce the weight of the piston and reduce the inertia force of the piston connecting rod mechanism.

[0030] Specifically, if Figures 1 to 3 As shown, the piston upper body 1 is made of cast steel and has a bowl-shaped structure. The inner surface of the piston upper body 1 is provided with a combustion chamber in which the fuel or propellant burns to generate high-temperature combustion gas.

[0031] In one embodiment, the combustion chamber is an ω-shaped combustion chamber, which has the effect of forming a vortex on the inhaled gas, that is, the gas inhaled into the combustion chamber has a certain flow rate under the action of inertia force, and the ω-shaped combustion chamber wall has a guiding effect on the airflow, thus forming a vortex. In addition, the ω-shaped combustion chamber has a small opening, and when the piston moves upward, there is an obvious squeezing effect, which squeezes all the gas into the ω-shaped combustion chamber. The flow rate of the squeezing airflow is relatively large, and the exhaust gas can be discharged more cleanly, more fresh air is inhaled, the diesel atomization and mixing are more uniform, the gas has more opportunities to be heated, and the mixed gas is easy to be compressed and exploded, which reduces the requirements for the fuel supply system, and also reduces the growth rate of the maximum combustion pressure, the engine works softly, and the thermal efficiency is higher.

[0032] The piston skirt 2 is made of aluminum alloy, and its top surface 21 has a groove that matches the outer surface 11 of the piston upper body 1, which is used to be fixedly connected to the piston upper body 1 to form an entire steel-aluminum structure piston, so that the steel-aluminum structure piston has two composite materials of cast steel and aluminum alloy. The piston upper body made of cast steel can be compatible with high-temperature combustion in the combustion chamber and improve the heat load capacity of the engine combustion chamber. At the same time, the piston skirt made of aluminum alloy can reduce the weight of the piston and reduce the inertia force of the piston connecting rod mechanism.

[0033] In one embodiment, the piston skirt 2 further includes: an inner cooling oil channel, a piston ring groove and a piston pin hole.

[0034] In one embodiment, the outer surface of the piston upper body 1 is provided with a plurality of positioning bosses 12, and the top surface of the piston skirt 2 is provided with a plurality of positioning holes 22 adapted to the positioning bosses 12. When the piston skirt 2 is fixedly connected to the piston upper body 1, positioning is performed through the positioning bosses 12 and the positioning holes 22, so that the cast aluminum piston skirt and the piston upper body are better combined together.

[0035] In one embodiment, the positioning bosses 12 are evenly distributed along the circumference of the piston upper body 1 , and the positioning holes 22 are evenly distributed along the circumference of the piston skirt 2 .

[0036] In one embodiment, if Figure 3 and Figure 4 As shown, the outer surface of the piston upper body 1 and the top surface of the piston skirt 2 are ω-shaped and match each other.

[0037] In summary, if Figure 4 As shown, when working, the steel-aluminum structure piston is arranged in the cylinder sleeve 3, the piston upper body is made of cast steel material, and the piston skirt is made of aluminum alloy material. The ω-shaped combustion chamber of the cast steel piston upper body can be compatible with high-temperature combustion in the combustion chamber, improving the heat load capacity of the engine combustion chamber, while the aluminum alloy piston skirt can reduce the weight of the piston and reduce the inertia force of the piston connecting rod mechanism.

[0038] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0039] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A steel-aluminum structure piston, characterized in that: include: The piston upper body is made of cast steel and is a bowl-shaped structure with a combustion chamber provided on its inner surface; And a piston skirt, which is made of aluminum alloy and is fixedly connected to the piston upper body; the top surface of the piston skirt has a groove that is adapted to the outer surface of the piston upper body.

2. The steel-aluminum structure piston according to claim 1, characterized in that: The combustion chamber of the piston upper body is an ω-shaped combustion chamber.

3. The steel-aluminum structure piston according to claim 1, characterized in that: The piston skirt also includes: an inner cooling oil channel, a piston ring groove and a piston pin hole.

4. The steel-aluminum structure piston according to claim 1, characterized in that: The outer surface of the piston upper body is provided with a plurality of positioning bosses, and the top surface of the piston skirt is provided with a plurality of positioning holes matched with the positioning bosses.

5. The steel-aluminum structure piston according to claim 4, characterized in that: The positioning bosses are evenly distributed along the circumference of the piston upper body, and the positioning holes are evenly distributed along the circumference of the piston skirt.

6. The steel-aluminum structure piston according to claim 2, characterized in that: The outer surface of the piston upper body and the top surface of the piston skirt are in an ω-shape that matches each other.

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