Composite connection type piston
By designing the piston top and piston head as separate structures, the problems of difficult processing and insufficient sealing of traditional piston cooling grooves are solved, achieving convenient processing and efficient heat exchange.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- LONGYAN YOULI TECHNOLOGY CO LTD
- Filing Date
- 2025-07-16
- Publication Date
- 2026-05-15
AI Technical Summary
The inward convex structure of the skirt near the pin hole of a traditional one-piece piston increases the wall thickness, making the cooling groove difficult to process and resulting in insufficient sealing.
The piston top and piston head are separate structures, while the piston top and piston skirt are integrally formed and connected by a sealing ring and a fixing plate, which facilitates the processing of the cooling groove and enhances the sealing performance.
It simplifies the processing of the cooling tank, improves sealing and stability, and enhances heat exchange efficiency and sealing area.
Smart Images
Figure CN224244971U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of piston technology, specifically to a composite connection piston. Background Technology
[0002] As a core moving component of an internal combustion engine, the piston's structural design directly affects the engine's combustion efficiency, mechanical strength, and thermal management performance. Traditional pistons are typically manufactured using a one-piece molding process, primarily with aluminum alloys, and are formed through casting or forging to meet requirements for lightweight and high strength. In traditional designs, the piston structure mainly includes the top, annular groove area, piston skirt, and pin bore. Among these, the piston skirt, as a guiding and load-bearing component, has a particularly critical structural design.
[0003] Traditional one-piece pistons typically feature an inwardly convex skirt near the pin bore, increasing the wall thickness in this area to enhance structural strength and load-bearing capacity at the pin bore. This design effectively disperses lateral forces experienced by the piston during reciprocating motion, reducing stress concentration in the pin bore area and thus extending piston life. However, this inwardly convex structure also introduces certain manufacturing limitations, particularly in the machining of piston cooling channels. The increased skirt wall thickness near the pin bore leads to greater material accumulation in this area, obstructing the tool feed path and increasing machining difficulty if cooling oil channels or cooling channels are to be machined inside the piston. Utility Model Content
[0004] The purpose of this invention is to address the problems existing in the background technology by proposing a composite connection piston.
[0005] The technical solution of this utility model is: a composite connecting piston, including a piston top, a piston head, and a piston skirt;
[0006] The piston head is located between the piston top and the piston skirt. The piston top and piston head are separate structures, while the piston head and piston skirt are integrally formed structures. A cooling groove is formed at the bottom end of the piston top. A sealing ring is provided at the bottom end of the piston top, located on the outer periphery of the cooling groove. A sealing groove is formed at the upper end of the piston head for the sealing ring to be inserted. Two fixing plates are connected side by side at the bottom end of the piston top. A second pin hole is formed on the fixing plate. Two through holes are formed on the piston head for the two fixing plates to pass through. An oil ring groove and two compression ring grooves are formed on the outer periphery of the piston head. The oil ring groove is located below the two compression ring grooves. A first pin hole is formed at both ends of the piston skirt.
[0007] Preferably, limit blocks are provided on the inner sides of both air ring grooves, and the limit blocks do not extend beyond the edge of the air ring groove.
[0008] Preferably, the midpoints of the two limiting blocks are connected through the center of the piston head.
[0009] Preferably, the piston head has multiple oil holes, and the inner cavity of the piston skirt is connected to the inner cavity of the cooling groove through the oil holes.
[0010] Preferably, a combustion chamber recess is provided at the center of the piston top.
[0011] Preferably, the two first pin holes and the two second pin holes are coaxially arranged, and the diameter of the first pin hole is equal to the diameter of the second pin hole.
[0012] Compared with the prior art, the above-mentioned technical solution of this utility model has the following beneficial technical effects:
[0013] Traditional one-piece pistons typically have an inwardly convex skirt near the pin hole, which increases the skirt wall thickness at the pin hole but hinders the machining of the cooling groove. In this technical solution, the piston top and piston head are designed as separate parts, making the cooling groove easier to machine. The piston top, piston head, and piston skirt are integrally connected by a pin, resulting in high stability. Furthermore, by inserting the sealing ring into the sealing groove, the piston top and piston head are less prone to loosening, and the sealing area is increased. Attached Figure Description
[0014] Figure 1 and Figure 2 All of these are schematic diagrams of the structure of this utility model.
[0015] Figure 3 and Figure 4 All are exploded views of this utility model.
[0016] Figure 5 for Figure 1 A magnified schematic diagram of the structure at point A.
[0017] Reference numerals: 1. Piston top; 101. Combustion chamber recess; 102. Cooling groove; 2. Piston head; 201. Combustion ring groove; 202. Oil ring groove; 203. Perforation; 204. Sealing groove; 205. Oil hole; 3. Piston skirt; 301. First pin hole; 4. Fixing plate; 401. Second pin hole; 5. Sealing ring; 6. Limiting block. Detailed Implementation
[0018] Example 1
[0019] like Figure 1-4 As shown, the present invention proposes a composite connecting piston, including a piston top 1, a piston head 2, and a piston skirt 3.
[0020] The piston head 2 is located between the piston top 1 and the piston skirt 3. The piston top 1 and piston head 2 are separate structures, while the piston head 2 and piston skirt 3 are integrally formed structures. A combustion chamber recess 101 is provided at the center of the piston top 1. The main function of the combustion chamber recess 101 is to optimize the combustion process and control the flame propagation path. This specially designed recess, together with the cylinder head, constitutes the combustion chamber space. Its shape directly affects the intensity of air vortex and the distribution of air-fuel mixture, thereby improving combustion efficiency. The geometric structure of the recess, such as bowl-shaped, ω-shaped, or bathtub-shaped, can guide the airflow to form stronger tumble and squeeze flow, promoting full mixing of fuel and air, while controlling the flame propagation speed to avoid knocking. In direct injection engines, the recess can also guide the direction of fuel spray, ensuring that the fuel is atomized and burned at the optimal position. In addition, the volume of the recess directly affects the compression ratio of the engine, thereby affecting power output and thermal efficiency. The rationally designed recesses can also reduce the combustion chamber surface area ratio, reduce heat loss, and reduce the generation of harmful emissions; a cooling groove 102 is provided at the bottom of the piston top 1, and multiple oil holes 205 are provided on the piston head 2. The inner cavity of the piston skirt 3 is connected to the inner cavity of the cooling groove 102 through the oil holes 205; a sealing ring 5 is provided at the bottom of the piston top 1, and the sealing ring 5 is located on the outer periphery of the cooling groove 102. A sealing groove 204 is provided at the upper end of the piston head 2 for the sealing ring 5 to be inserted; two fixing plates 4 are connected side by side at the bottom of the piston top 1. A second pin hole 401 is provided on the fixing plate 4. Two through holes 203 are provided on the piston head 2 for the two fixing plates 4 to pass through respectively; an oil ring groove 202 and two gas ring grooves 201 are provided on the outer periphery of the piston head 2. The oil ring groove 202 is located below the two gas ring grooves 201; a first pin hole 301 is provided at both ends of the piston skirt 3.
[0021] In this invention, when the piston reaches near its bottom dead center, a nozzle sprays pressurized oil onto the inner surface of the piston bottom. Under the influence of inertia and piston movement, the sprayed oil enters the cooling groove 102 through the oil hole 205 at the bottom of the piston, and then enters the annular cooling oil chamber. After entering the annular oil chamber, the oil does not flow rapidly in one direction like in a pipe. Due to the high-speed reciprocating motion of the piston, the oil in the cooling groove 102 experiences violent oscillations and turbulence. This motion greatly enhances the heat exchange efficiency between the oil and the high-temperature metal wall, fully absorbing heat. The heated oil, under the influence of piston movement and gravity, is thrown out through the oil hole 205 on the other side and falls back into the oil pan. Some of the splashed oil also participates in the lubrication of the piston skirt 3.
[0022] In this technical solution, the piston top 1 and piston head 2 are set separately to facilitate the processing of the cooling groove 102 and reduce the processing difficulty. The two fixing plates 4 are respectively aligned with the two through holes 203 and inserted, and then the fixing plates 4 are connected to the piston skirt 3, realizing the connection between the piston top 1 and piston head 2. The sealing ring 5 is inserted into the inner side of the sealing groove 204, thereby improving the sealing performance at the connection between the piston top 1 and piston head 2.
[0023] Regarding the installation sequence of the combined oil ring: first install the spiral bushing, ensuring it is fully embedded in the bottom of the oil ring groove; then install the upper scraper, gently pressing it in with a special tool or your finger; finally install the lower scraper, ensuring the two scrapers are parallel and do not overlap. It should be noted that the oil ring opening should be staggered from the gas ring opening to avoid oil control failure.
[0024] Example 2
[0025] like Figure 1 and Figure 5 As shown, the present invention proposes a composite connection piston. Compared with Embodiment 1, in this embodiment, limit blocks 6 are provided on the inner side of both gas ring grooves 201, and the limit blocks 6 do not exceed the edge position of the gas ring grooves 201; the midpoint of the two limit blocks 6 is connected through the center of the piston head 2.
[0026] In this embodiment, when installing the first gas ring, piston ring expanders are used to carefully open the gas ring to avoid excessive deformation and breakage. The ring is slowly placed into the first ring groove, ensuring that the "TOP" mark faces upwards. The corresponding limiting block 6 is placed inside the notch of the ring, thereby limiting the ring. Similarly, piston ring expanders are used for installation. Note that the second gas ring is a conical or anti-twisted design. Installing it backwards will cause abnormal oil scraping. During installation, ensure that it is 180° off from the opening of the first gas ring to avoid direct gas leakage. The two limiting blocks 6 in this technical solution are exactly 180° off to achieve auxiliary positioning of the two gas rings.
[0027] Example 3
[0028] like Figure 3 and Figure 4 As shown, in this embodiment of the present invention, a composite connecting piston is proposed. Compared with the first embodiment, in this embodiment, the two first pin holes 301 and the two second pin holes 401 are coaxially arranged, and the diameter of the first pin hole 301 is equal to the diameter of the second pin hole 401.
[0029] In this embodiment, the second pin hole 401 and the first pin hole 301 are provided for the piston pin to pass through, so that the piston pin passes through the first pin hole 301, the second pin hole 401 and the pin hole on the connecting rod, thereby completing the connection between the connecting rod and the piston. In this process, the piston top 1 and the piston head 2 are also installed and connected.
[0030] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.
Claims
1. A composite connection piston, characterized in that, It includes the piston top (1), piston head (2) and piston skirt (3); The piston head (2) is located between the piston top (1) and the piston skirt (3). The piston top (1) and the piston head (2) are separate structures, while the piston head (2) and the piston skirt (3) are integrally formed structures. A cooling groove (102) is provided at the bottom end of the piston top (1). A sealing ring (5) is provided at the bottom end of the piston top (1). The sealing ring (5) is located on the outer periphery of the cooling groove (102). A sealing groove (204) is provided at the upper end of the piston head (2) for the sealing ring (5) to be inserted. Two fixing plates (4) are connected side by side at the bottom of the piston top (1). The fixing plates (4) have a second pin hole (401). The piston head (2) has two through holes (203) for the two fixing plates (4) to pass through. The piston head (2) has an oil ring groove (202) and two gas ring grooves (201) on its outer periphery. The oil ring groove (202) is located below the two gas ring grooves (201). The piston skirt (3) has a first pin hole (301) at both ends.
2. The composite connection piston according to claim 1, characterized in that, Limiting blocks (6) are provided on the inner side of both air ring grooves (201), and the limiting blocks (6) do not extend beyond the edge of the air ring grooves (201).
3. A composite connecting piston according to claim 2, characterized in that, The midpoints of the two limiting blocks (6) are connected through the center of the piston head (2).
4. A composite connecting piston according to claim 1, characterized in that, Multiple oil holes (205) are provided on the piston head (2), and the inner cavity of the piston skirt (3) is connected to the inner cavity of the cooling groove (102) through the oil holes (205).
5. A composite connecting piston according to claim 1, characterized in that, A combustion chamber recess (101) is provided at the center of the piston top (1).
6. A composite connecting piston according to claim 1, characterized in that, The two first pin holes (301) and the two second pin holes (401) are coaxially arranged, and the diameter of the first pin hole (301) is equal to the diameter of the second pin hole (401).