An asymmetric small-clearance piston structure for CH primary discharge

Abstract

This invention discloses an asymmetric small-clearance piston structure, including a piston, cylinder head, cylinder block, and cylinder liner. The cylinder head is mounted on the upper part of the cylinder block. The cylinder block has a cylinder bore, and the cylinder liner is installed within the cylinder bore. The piston is installed within the cylinder liner. The piston includes a head, a combustion chamber, and a skirt. The head has a fire land, with the combustion chamber formed on its top surface and several piston rings formed on its side surface. The lower part connects to the skirt. The head has an elliptical structure. The clearance between the fire land and the main thrust surface is P, the clearance between the fire land and the secondary thrust surface is Q, and the clearance between the fire land and the non-thrust surface is L, where P ≥ Q > L. This invention has advantages such as high reliability, reduced fuel entry into the clearance space, and improved combustion efficiency.

Description

Technical Field

[0001] This invention relates to the field of engine piston technology, and in particular to an asymmetric small side clearance piston structure with reduced CH original discharge. Background Technology

[0002] The piston in a car is like the central part of the engine, playing a crucial role during engine startup. The piston withstands gas pressure and, through the piston pin, drives the connecting rod to rotate the crankshaft. The piston crown is also part of the combustion chamber. Generally, car pistons are divided into three main categories: diesel engine pistons, gasoline engine pistons, and general-purpose pistons.

[0003] There is a side clearance space between the cylinder head, piston, and cylinder liner. Studies have found that a small side clearance space between the piston head and cylinder liner is beneficial for combustion, but thermal expansion during piston operation and manufacturing deviations lead to abnormal wear, which is detrimental to reliability. A large side clearance space between the piston head and cylinder liner is beneficial for wear resistance, but also beneficial for combustion. In addition, this side clearance space is narrow and far from the combustion chamber. When fuel enters the side clearance space, the fuel cannot burn completely, resulting in excessive CH emissions.

[0004] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0005] The main objective of this invention is to propose an asymmetric elliptical piston head, which adjusts the size of the side clearance space of each part of the piston head to achieve a balance between combustion and piston reliability.

[0006] Therefore, this invention proposes an asymmetric small-side-gap piston structure for the CH original discharge.

[0007] Preferably, the present invention may also have the following technical features:

[0008] An asymmetric small-clearance piston structure includes a piston, a cylinder head, a cylinder block, and a cylinder liner. The cylinder head is mounted on the upper part of the cylinder block. The cylinder block has a cylinder bore, and the cylinder liner is installed in the cylinder bore. The piston is installed in the cylinder liner. The piston includes a head, a combustion chamber, and a skirt. The head has a fire land, the combustion chamber is opened on its top surface, and a plurality of piston rings are opened on its side surface. The lower part is connected to the skirt. The head has an elliptical structure. The clearance between the fire land and the main thrust surface is P, the clearance between the fire land and the secondary thrust surface is Q, and the clearance between the non-thrust surface is L, and P ≥ Q > L.

[0009] Furthermore, the piston ring closest to the top surface of the piston is the first piston ring, and the piston head between the first piston ring and the top surface of the piston is the fire shore.

[0010] Furthermore, a sealing ring is fitted inside the first piston ring.

[0011] Furthermore, P > Q.

[0012] Furthermore, the difference between P and Q is 0 to 0.1 mm.

[0013] Furthermore, the difference between Q and L is 0.1 to 0.2 mm.

[0014] Furthermore, the piston head has an asymmetrical elliptical structure, and the two minor axes of the ellipse are asymmetrical; wherein, the two minor axes of the asymmetrical ellipse are minor axis I and minor axis II, and the length of minor axis I is less than the length of minor axis II; the fire shore side corresponding to minor axis I is on the same side as the main thrust surface, forming a side clearance P; the fire shore side corresponding to minor axis II is on the same side as the secondary thrust surface, forming a side clearance Q.

[0015] The beneficial effects of this invention compared with the prior art include: In this invention, by controlling the side clearance values ​​of P, Q, and L, the side clearance of the main thrust surface and the secondary thrust surface is larger, ensuring reliability, while the side clearance of the non-thrust surface is smaller, reducing fuel entering the side clearance space and taking into account combustion efficiency. Attached Figure Description

[0016] Figure 1 This is an installation diagram of the present invention.

[0017] Figure 2 and Figure 3 This is a schematic diagram of the piston head and cylinder liner side clearance of the present invention.

[0018] 1. Cylinder head; 2. Cylinder liner; 3. Piston; 4. Combustion chamber; 5. Side clearance space; 31. Main thrust surface; 32. Secondary thrust surface; 33. Non-thrust surface. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to specific embodiments and the accompanying drawings. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope or application of the present invention.

[0020] Non-limiting and non-exclusive embodiments will be described with reference to the following figures, wherein the same reference numerals denote the same parts unless otherwise specifically stated.

[0021] like Figures 1-3An asymmetric small-clearance piston structure is shown, comprising a piston 3, a cylinder head 1, a cylinder block, and a cylinder liner 2. The cylinder head 1 is mounted on the upper part of the cylinder block. The cylinder block has a cylinder bore, and the cylinder liner 2 is installed in the cylinder bore. The piston 3 is installed in the cylinder liner 2. The piston 3 includes a head, a combustion chamber 4, and a skirt. The head has a fire shore 35, with the combustion chamber 4 opening on its top surface and several piston rings opening on its side surface. The lower part is connected to the skirt 36. The head has an elliptical structure. The clearance between the fire shore 35 and the main thrust surface 31 is P, the clearance between the fire shore 35 and the secondary thrust surface 32 is Q, and the clearance between the non-thrust surface 33 and the main thrust surface 32 is L, where P ≥ Q > L. In this embodiment, the clearances of the main thrust surface 31 and the secondary thrust surface 32 are relatively large to ensure reliability, while the clearance of the non-thrust surface 33 is small to reduce fuel entry and balance combustion efficiency. More specifically, the piston ring closest to the top surface of the piston is the first piston ring 37, and the piston head between the first piston ring 37 and the top surface of the piston is the fire land 35. During operation, after the first piston ring 37 is fitted with a sealing ring, the sealing ring separates the fire land 35 from the lower part of the piston head. The piston is an asymmetric side clearance piston.

[0022] Preferably, P > Q. For example, the difference between P and Q is 0 to 0.1 mm, i.e., PQ = 0 to 0.1 mm. This side clearance can prevent or reduce the piston, ensuring that the piston moves back and forth smoothly.

[0023] More specifically, the difference between Q and L is 0.1 to 0.2 mm, i.e., QL = 0.1 to 0.2 mm.

[0024] In some implementations, refer to Figures 2-3 The head has an asymmetrical elliptical structure, and the two minor axes of the asymmetrical ellipse are asymmetrical; specifically, the two minor axes of the asymmetrical ellipse are minor axis I39 and minor axis II38, and the length of minor axis I39 is less than the length of minor axis II38. The fire support side corresponding to minor axis I39 is on the same side as the main thrust surface 31; the fire support side corresponding to minor axis II38 is on the same side as the secondary thrust surface 32.

[0025] Those skilled in the art will recognize that numerous variations are possible with respect to the above description, and the embodiments and figures are merely for describing one or more specific implementations.

[0026] Although exemplary embodiments of the invention have been described and illustrated, those skilled in the art will understand that various changes and substitutions can be made thereto without departing from the spirit of the invention. Furthermore, many modifications can be made to adapt specific situations to the doctrine of the invention without departing from the central concepts of the invention described herein. Therefore, the invention is not limited to the specific embodiments disclosed herein, but may include all embodiments and equivalents that fall within the scope of the invention.

Claims

1. An asymmetric small-clearance piston structure, comprising a piston, a cylinder head, a cylinder block, and a cylinder liner, wherein the cylinder head is mounted on the upper part of the cylinder block; the cylinder block has a cylinder bore, and the cylinder liner is installed in the cylinder bore; the piston is installed in the cylinder liner, the piston comprising a head, a combustion chamber, and a skirt, the head having a fire land, the combustion chamber being formed on its top surface, a plurality of piston rings being formed on its side surface, and the lower part being connected to the skirt; characterized in that: The head has an elliptical structure, wherein the side clearance between the fire shore and the main thrust surface is P, the side clearance between the secondary thrust surface is Q, and the side clearance between the non-thrust surface is L, and P > Q > L; The difference between P and Q is 0~0.1mm; The difference between Q and L is 0.1~0.2 mm; The piston head has an asymmetrical elliptical structure, with the two minor axes of the ellipse being asymmetrical. The two minor axes of the asymmetrical ellipse are minor axis I and minor axis II, with the length of minor axis I being less than the length of minor axis II. The fire shore side corresponding to minor axis I is on the same side as the main thrust surface, forming a side clearance P. The fire shore side corresponding to minor axis II is on the same side as the secondary thrust surface, forming a side clearance Q.

2. The asymmetric small-clearance piston structure as described in claim 1, characterized in that: The piston ring closest to the top surface of the piston is the first piston ring, and the piston head between the first piston ring and the top surface of the piston is the fire shore.

3. The asymmetric small-clearance piston structure as described in claim 2, characterized in that: A sealing ring is assembled inside the first piston ring.

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