Engine combustion chamber
By adding inclined air guide surfaces in the engine combustion chamber and optimizing the piston structure, the problem of low gas flow rate was solved, achieving higher combustion efficiency and lower fuel consumption.
Patent Information
- Application Number
- CN202520004274.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2035-01-02
AI Technical Summary
The gas flow rate in the combustion chamber of existing engines is low, which affects combustion efficiency and performance. Existing methods such as supercharging and shape optimization have limited improvements.
Inclined gas-guiding surfaces are added to the cylinder head and cylinder combustion chamber to create an exhaust effect, increase gas flow rate and mixing uniformity, and optimize the gas flow path by designing the gas-guiding surfaces and piston structure.
It increases the gas flow rate in the combustion chamber, enhances the oil-gas mixing uniformity and flame propagation speed, and improves engine performance and fuel consumption efficiency.
Smart Images
Figure CN223482760U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of engine combustion chamber technology and relates to an engine combustion chamber. Background Technology
[0002] The engine combustion chamber is the part of the engine that provides space for the combustion of the air-fuel mixture, and it has a significant impact on the engine's performance, efficiency, and economy. The gas flow velocity and direction within the engine combustion chamber affect the effectiveness of the air-fuel mixture and the speed of flame propagation during combustion. The faster the airflow velocity, the better the air-fuel mixture, the faster the flame propagation speed, and the faster the in-cylinder combustion speed, resulting in a higher efficiency in converting chemical energy into mechanical kinetic energy. Therefore, improving the gas flow velocity within the engine's combustion chamber is crucial. Factors affecting the gas flow velocity within the combustion chamber include: the velocity of the gas at the intake end and the resistance to gas flow within the combustion chamber. Increasing the gas flow velocity at the intake end is generally achieved in two ways: one is to increase the pressure at the beginning of the intake, such as by using a turbocharger; the other is to decrease the pressure at the end, such as by increasing in-cylinder scavenging to reduce the residual high-temperature gas in the cylinder, thereby lowering the pressure. Increasing scavenging requires increasing the overlap angle between the intake and exhaust, which means that the fresh air entering the combustion chamber is expelled again, so this increase is very limited. Increasing the pressure at the intake end requires adding a pressurization device, which also consumes engine power to maintain operation, so it is a trade-off of cost for performance.
[0003] To reduce the flow resistance of gas in the combustion chamber, the general approach is to optimize the shape and surface quality of the combustion chamber to reduce the obstruction encountered by the intake air flow. However, the shape of the combustion chamber is limited by the valve arrangement and the necessary shape to direct the intake air in the desired direction. Furthermore, the improvement of surface quality is also limited due to the influence of production methods and costs.
[0004] To solve the above problems, the structure of the existing combustion chamber needs to be optimized to increase the flow rate inside the combustion chamber, thereby improving engine performance. Utility Model Content
[0005] In view of this, the present invention provides an engine combustion chamber in which an inclined air guide surface is added to both the cylinder head combustion chamber and the cylinder block combustion chamber. The two air guide surfaces are matched with each other, so that the air intake of the combustion chamber is supplemented by the suction effect generated by the movement of the two air guide surfaces, thereby increasing the air velocity in the combustion chamber and thus improving the overall performance of the engine.
[0006] This utility model discloses an engine combustion chamber, including a cylinder block combustion chamber formed by a cylinder wall and a piston top surface, and a cylinder head combustion chamber formed on the cylinder head at a position corresponding to the cylinder block combustion chamber; the bottom of the cylinder head combustion chamber is provided with an inclined upper air guide surface, and the piston top surface is provided with a lower air guide surface at a position corresponding to the upper air guide surface, the lower air guide surface being conformally shaped to the upper air guide surface.
[0007] Furthermore, the top of the upper air guide surface is inclined towards the central axis of the cylinder head combustion chamber, and the bottom of the upper air guide surface is inclined away from the central axis of the cylinder head combustion chamber, so that the upper air guide surface forms a conical structure with a radial dimension that gradually increases from top to bottom.
[0008] Furthermore, the upper air guide surface and the lower air guide surface are coaxially arranged, and there is a minimum gap s between the upper air guide surface and the lower air guide surface, the value of which is in the range of 0.1 to 0.4 mm.
[0009] Furthermore, the cylinder head combustion chamber has a hemispherical structure, and the upper air guide surface is connected to the cylinder head combustion chamber. The cylinder head combustion chamber divides the upper air guide surface into upper air guide region I, upper air guide region III, upper air guide region II and upper air guide region IV arranged sequentially along the circumference. Upper air guide region I is located on the engine intake side, and upper air guide region II is located on the engine exhaust side.
[0010] Furthermore, the piston top surface has a ridge-shaped structure with a central bulge, and the piston top surface is recessed downward to form multiple clearance pits. These clearance pits divide the lower air guiding surface into lower air guiding region I, lower air guiding region III, lower air guiding region II, and lower air guiding region IV arranged sequentially along the circumference. The positions of lower air guiding region I and lower air guiding region II correspond one-to-one with those of upper air guiding region I and upper air guiding region II, respectively.
[0011] Furthermore, the periphery of the lower air guiding region III is recessed downward along the axial direction to form a sunken step I, the position of which corresponds to the upper air guiding region III.
[0012] Furthermore, the periphery of the lower air guiding region IV is recessed downward along the axial direction to form a sunken step II, the position of which corresponds to the upper air guiding region IV.
[0013] The beneficial effects of this utility model are:
[0014] This utility model discloses an engine combustion chamber. An inclined air guide surface is added to both the cylinder head combustion chamber and the cylinder block combustion chamber. Furthermore, the upper and lower air guide surfaces are divided into multiple air guide regions. Combined with the addition of two downward-sloping steps, this alters the volume change rate of the effective and ineffective airflow direction regions. The volume change rate of the effective airflow direction region increases, while the volume change rate of the ineffective airflow direction region decreases. This results in a significant local suction effect in the effective airflow direction region of the combustion chamber, guiding more gas towards that region. Simultaneously, the suction effect compensates for the kinetic energy loss of the airflow, increasing the kinetic energy of the final tumbling gas. This increased kinetic energy leads to a higher gas velocity, resulting in more uniform fuel-air mixing, faster flame propagation during combustion, and more rapid combustion. This also improves the efficiency of converting chemical energy into mechanical energy, allowing for the use of less fuel under the same performance specifications, ultimately resulting in better emissions and lower fuel consumption. Attached Figure Description
[0015] Figure 1 This is a cross-sectional view of the combustion chamber of this utility model;
[0016] Figure 2 This is a bottom view of the cylinder head combustion chamber of this utility model;
[0017] Figure 3 This is a top view of the cylinder combustion chamber of this utility model. Detailed Implementation
[0018] It should be noted that in the description of this specification, the terms "upper," "lower," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In this embodiment, the axial direction is indicated by the accompanying drawings. Figure 1 In the vertical direction, in this embodiment, the lower air guiding area I, lower air guiding area II, lower air guiding area III, and lower air guiding area IV, as well as the upper air guiding area I, upper air guiding area II, upper air guiding area III, and upper air guiding area IV, are filled with color to facilitate the display. This is understandable to those skilled in the art and will not be elaborated here.
[0019] As shown in the figure, an embodiment of this utility model discloses an engine combustion chamber, including a cylinder block combustion chamber formed by the cylinder wall and piston top surface of the engine, and a cylinder head combustion chamber formed on the cylinder head at a position corresponding to the cylinder block combustion chamber. An inclined upper air guide surface 1 is provided at the bottom of the cylinder head combustion chamber, and a lower air guide surface 2 is provided on the piston top surface at a position corresponding to the upper air guide surface 1. The lower air guide surface 2 is conformally shaped to the upper air guide surface 1. In this embodiment, the top of the upper air guide surface 1 is inclined towards the central axis of the cylinder head combustion chamber, and the bottom of the upper air guide surface 1 is inclined away from the central axis of the cylinder head combustion chamber, so that the upper air guide surface 1 forms a conical structure with a radial dimension gradually increasing from top to bottom. In this embodiment, the inclination angle of the upper air guide surface 1 is α. The inclination angle α of the upper air guide surface 1 is designed according to the flow direction of the gas entering the combustion chamber and the direction in which the gas needs to be guided. In this embodiment, the inclination angle α of the upper air guide surface 1 is designed to be 15°. In this embodiment, the upper air guide surface 1 is not a complete air guide surface, but rather an annular curved surface machined at the bottom circumference of the cylinder head combustion chamber. This curved surface, after extension, becomes a complete conical surface, which is understandable to those skilled in the art and will not be elaborated upon here. Simultaneously, in this embodiment, the upper air guide surface 1 and the lower air guide surface 2 are coaxially arranged, with a minimum gap s between them. The minimum gap s ranges from 0.1 to 0.4 mm. The gap between the upper air guide surface 1 and the lower air guide surface 2 exists because the piston is constantly moving; therefore, a minimum gap is maintained between them to prevent the piston from impacting the cylinder head. When the piston reaches top dead center, the gap between the upper air guide surface 1 and the lower air guide surface 2 is the minimum gap s. To ensure normal piston operation and sufficient compression, the minimum gap s is typically set between 0.1 and 0.4 mm; in this embodiment, the minimum gap s is set to 0.2-0.3 mm.
[0020] In this embodiment, the cylinder head combustion chamber has a hemispherical structure, and the upper air guide surface 1 is connected to the cylinder head combustion chamber. The cylinder head combustion chamber divides the upper air guide surface 1 into upper air guide region I5, upper air guide region III3, upper air guide region II6 and upper air guide region IV4 arranged sequentially along the circumference. The engine has an intake side and an exhaust side. In this embodiment, the upper air guide region I5 is located on the engine intake side and the upper air guide region II6 is located on the engine exhaust side. Furthermore, in this embodiment, the piston top surface has a ridge-shaped structure with a raised center. The ridge-shaped structure refers to the piston top surface being high in the center and low around the edges, resembling a roof ridge. In fact, in this embodiment, the center of the piston top surface is also recessed to increase the combustion chamber volume. In addition, the piston top surface is recessed downward to form multiple clearance pits for the valves. The positions of the clearance pits need to be set according to the positions of the valves. These multiple clearance pits divide the lower air guide surface 2 into lower air guide regions I11, III7, II12 and IV8 arranged sequentially along the circumference. The positions of lower air guide regions I11 and II12 correspond one-to-one with the upper air guide regions I5 and II6, respectively. As shown in the figure, in this embodiment, the lower air guiding region I11 and the upper air guiding region I5 are positioned correspondingly and their areas are approximately equal (approximately equal means that their areas are similar, but not exactly the same); the lower air guiding region II12 and the upper air guiding region II6 are also positioned correspondingly and their areas are also approximately equal.
[0021] In this embodiment, the periphery of the lower air guiding region III7 is recessed downwards along the axial direction to form a sunken step I9, the position of which corresponds to the upper air guiding region III3; the periphery of the lower air guiding region IV8 is recessed downwards along the axial direction to form a sunken step II10, the position of which corresponds to the upper air guiding region IV4. As shown in the figure, the position of the sunken step I9 corresponds to the upper air guiding region III3, and the two are well-proportioned. In terms of area, the area of the sunken step I9 is slightly larger than that of the upper air guiding region III3 (slightly larger means that the area of the sunken step I9 is larger than that of the upper air guiding region III3, but the difference in area is not very large); similarly, the position of the sunken step II10 corresponds to the upper air guiding region IV4, and the two are well-proportioned, and the area of the sunken step II10 is slightly larger than that of the upper air guiding region IV4.
[0022] Therefore, in this embodiment, when the combustion chamber is working, the volume distribution of the combustion chamber after the cylinder block combustion chamber and the cylinder head combustion chamber overlap at different positions on the circumference when the piston reaches top dead center. In the effective intake airflow direction area, the overlapping area of the conical surfaces is large (the lower guide air area I11 overlaps with the upper guide air area I5, and the lower guide air area II12 overlaps with the upper guide air area II6), while the upper guide air surface 1 and the lower guide air surface 2 have small volumes due to their small fitting clearance. In the ineffective intake airflow direction area, the upper guide air surface 1 and the lower guide air surface 2 do not overlap (the positions of the upper guide air area III3 and the upper guide air area IV4 are different from those of the lower guide air area). The positions of region III7 and lower guide region IV8 do not overlap, but the positions of upper guide regions III3 and IV4 overlap with the positions of lower step I9 and lower step II10, resulting in a large volume. Thus, during the piston's downward stroke (i.e., the intake stroke), the volume change rate is large in the effective intake flow direction region and small in the ineffective intake flow direction region. This creates a significant local suction effect in the effective intake flow direction region, guiding more gas towards it. Simultaneously, the suction effect compensates for the kinetic energy loss of the airflow, increasing the kinetic energy of the final tumbling gas. This increased gas kinetic energy leads to higher gas velocity. Higher gas velocity results in more uniform fuel-air mixing, faster flame propagation during combustion, and more rapid combustion. This leads to higher efficiency in converting chemical energy into mechanical energy, meaning less fuel is used for the same performance, ultimately resulting in better emissions and lower fuel consumption.
[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.
Claims
1. An engine combustion chamber, characterized in that: It includes a cylinder block combustion chamber formed by the cylinder wall and the piston top surface, and a cylinder head combustion chamber formed on the cylinder head at the position corresponding to the cylinder block combustion chamber; the bottom of the cylinder head combustion chamber is provided with an inclined upper air guide surface, and the piston top surface is provided with a lower air guide surface at the position corresponding to the upper air guide surface, and the lower air guide surface is conformally shaped to the upper air guide surface.
2. The engine combustion chamber according to claim 1, characterized in that: The top of the upper air guide surface is inclined towards the central axis of the cylinder head combustion chamber, and the bottom of the upper air guide surface is inclined away from the central axis of the cylinder head combustion chamber, so that the upper air guide surface forms a conical structure with the radial dimension gradually increasing from top to bottom.
3. The engine combustion chamber according to claim 2, characterized in that: The upper air guide surface and the lower air guide surface are coaxially arranged, and there is a minimum gap s between the upper air guide surface and the lower air guide surface. The value of the minimum gap s ranges from 0.1 to 0.4 mm.
4. The engine combustion chamber according to claim 1, characterized in that: The cylinder head combustion chamber has a hemispherical structure. The upper air guide surface is connected to the cylinder head combustion chamber. The cylinder head combustion chamber divides the upper air guide surface into upper air guide region I, upper air guide region III, upper air guide region II and upper air guide region IV arranged sequentially along the circumference. Upper air guide region I is located on the engine intake side and upper air guide region II is located on the engine exhaust side.
5. The engine combustion chamber according to claim 4, characterized in that: The piston top surface has a roof-shaped structure with a central ridge. The piston top surface is recessed downward to form multiple clearance pits. These clearance pits divide the lower air guide surface into lower air guide region I, lower air guide region III, lower air guide region II, and lower air guide region IV arranged sequentially along the circumference. The positions of lower air guide region I and lower air guide region II correspond one-to-one with those of upper air guide region I and upper air guide region II, respectively.
6. The engine combustion chamber according to claim 5, characterized in that: The periphery of the lower air guiding region III is recessed downward along the axial direction to form a sunken step I, and the position of the sunken step I corresponds to that of the upper air guiding region III.
7. The engine combustion chamber according to claim 5, characterized in that: The periphery of the lower air guiding region IV is recessed downward along the axial direction to form a sunken step II, and the position of the sunken step II corresponds to that of the upper air guiding region IV.