Piston with special pin bore structure

Abstract

The application discloses a special-shaped pin hole structure piston and belongs to the technical field of aluminum piston structure of an internal combustion engine, and comprises a pin hole, characterized in that the pin hole profile mainly comprises a first curve segment, a second curve segment, a third curve segment and a fourth curve segment; the first curve segment is located between 45 DEG and 135 DEG of the pin hole, and is a circular arc with the center of the pin hole as the center and a diameter of a; the second curve segment is located between 225 DEG and 315 DEG of the pin hole, and is a circular arc with the center of the pin hole as the center and a diameter of b; the third curve segment and the fourth curve segment are symmetrically distributed on the two sides of the first curve segment and the second curve segment, and the third curve segment and the fourth curve segment are tangent to the first curve segment and the second curve segment respectively. Compared with the prior art, the application combines the advantages of the traditional horizontal elliptical pin hole and the vertical elliptical pin hole, strengthens the bearing capacity of the piston pin hole part, and reduces the stress concentration of the throat part of the piston combustion chamber.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum piston structure of internal combustion engine, in particular to a special-shaped pin hole structure piston. BACKGROUND

[0002] In order to reduce the contact stress between the piston pin hole and the piston pin and enhance the bearing capacity of the piston, the traditional aluminum piston of internal combustion engine often adopts an oval pin hole. In order to enhance the bearing capacity of the piston pin hole part, a transverse oval pin hole is often adopted, but the problem of increased stress at the throat of the combustion chamber exists. In order to reduce the stress concentration at the throat of the combustion chamber, a longitudinal oval pin hole is adopted, but the bearing capacity of the pin hole part is reduced. SUMMARY

[0003] The present application aims to overcome the shortcomings of the traditional technology, and provide a special-shaped pin hole structure piston which can enhance the bearing capacity of the pin hole part and reduce the stress concentration at the throat of the combustion chamber.

[0004] The special-shaped pin hole structure piston provided by the present application comprises a pin hole, and the pin hole profile mainly comprises a first curve segment, a second curve segment, a third curve segment and a fourth curve segment. The first curve segment is located between 45° and 135° of the pin hole, and is a circular arc with the center of the pin hole as the center and a diameter of a. The second curve segment is located between 225° and 315° of the pin hole, and is a circular arc with the center of the pin hole as the center and a diameter of b. The third curve segment and the fourth curve segment are symmetrically distributed on the two sides of the first curve segment and the second curve segment, and the third curve segment and the fourth curve segment are tangent to the first curve segment and the second curve segment respectively. The third curve segment and the fourth curve segment are both elliptical arcs with the center of the pin hole as the center, a long axis size of a and a short axis size of b.

[0005] Compared with the traditional transverse oval pin hole and longitudinal oval pin hole, the pin hole profile of the special-shaped pin hole structure piston provided by the present application has the following advantages. Under the condition that other specifications of the piston are the same, the transverse diameter size of the pin hole of the present application is between the transverse diameter sizes of the transverse oval pin hole and the longitudinal oval pin hole, and the vertex of the pin hole of the present application in the longitudinal direction coincides with the vertex position of the longitudinal oval pin hole. Therefore, the pin hole profile of the present application combines the advantages of the traditional transverse oval pin hole and the longitudinal oval pin hole, which not only enhances the bearing capacity of the piston pin hole part, but also reduces the stress concentration at the throat of the combustion chamber. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 is a structural schematic diagram of the present application;

[0007] Figure 2 is a profile comparison diagram of the present application and the traditional oval pin hole.

[0008] In the drawings, the correspondence between the component names and the drawing numbers is as follows:

[0009] 1, first curve segment; 2, second curve segment; 3, third curve segment; 4, fourth curve segment; A, pin hole profile of the present application; B, transverse oval pin hole; C, longitudinal oval pin hole. DETAILED DESCRIPTION

[0010] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0011] The present application provides a special-shaped pin hole structure piston, which comprises a pin hole. Figure 1 The pin hole profile A mainly comprises a first curve segment 1, a second curve segment 2, a third curve segment 3 and a fourth curve segment 4. The first curve segment 1 is located between 45° and 135° of the pin hole, and is a circular arc with the center point of the pin hole as the center and a diameter of a. The second curve segment 2 is located between 225° and 315° of the pin hole, and is a circular arc with the center point of the pin hole as the center and a diameter of b. The third curve segment 3 and the fourth curve segment 4 are symmetrically distributed on the two sides of the first curve segment 1 and the second curve segment 2, and are tangent to the first curve segment 1 and the second curve segment 2, respectively. The third curve segment 3 and the fourth curve segment 4 are both elliptical arcs with the center point of the pin hole as the center, a major axis size of a and a minor axis size of b.

[0012] The present application provides a special-shaped pin hole structure piston, which comprises a pin hole. Figure 2 Under the condition that other specifications of the piston are the same, in comparison with the traditional transverse oval pin hole B and the longitudinal oval pin hole C, the pin hole profile A of the present application has the same vertex position as the longitudinal oval pin hole C in the longitudinal direction, and the diameter size of the pin hole profile A of the present application is between the diameter sizes of the transverse oval pin hole B and the longitudinal oval pin hole C in the transverse direction.

[0013] As can be seen from the above, the pin hole profile A of the present application combines the advantages of the traditional transverse oval pin hole B and the longitudinal oval pin hole C, thereby enhancing the bearing capacity of the piston pin hole part and reducing the stress concentration of the piston combustion chamber throat part.

Claims

1. A profiled pin bore construction piston comprising a pin bore, characterized in that, The profile of the pin hole is composed of a first curve segment (1), a second curve segment (2), a third curve segment (3) and a fourth curve segment (4); The first curve segment (1) is located between 45° and 135° of the pin hole, and is a circular arc with the center at the center point of the pin hole and a diameter of a; The second curve segment (2) is located between 225° and 315° of the pin hole, and is a circular arc with the center at the center point of the pin hole and a diameter of b; The third curve segment (3) and the fourth curve segment (4) are symmetrically distributed on the two sides of the first curve segment (1) and the second curve segment (2), and are tangent to the first curve segment (1) and the second curve segment (2), respectively; the third curve segment (3) and the fourth curve segment (4) are both elliptical arcs with the center at the center point of the pin hole, a major axis size of a and a minor axis size of b.

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