Cylinder cover, engine, power assembly and vehicle

Abstract

The utility model discloses a cylinder cover, an engine, a power assembly and a vehicle. The cylinder cover is used for forming a combustion chamber with a piston in a surrounding mode, the cylinder cover comprises a cylinder cover body, and a top wall is arranged at the top of the cylinder cover body. A side wall is arranged on the side portion of the air cylinder cover body, the top edge of the side wall is of an arc shape protruding towards the top wall and connected with the edge of the top wall, and the curvature of the arc shape is unchanged or continuously changed. According to the cylinder cover, the arc protruding towards the top is arranged at the top of the side wall, the top of the side wall is connected and flush with the top wall, a uniform high-speed airflow layer is effectively formed at the top of a combustion chamber, the airflow structure of the whole combustion chamber is further made to be of a standard interlayer structure, flame propagation uniformity is improved, and combustion efficiency is improved. And the knocking risk is reduced.

Description

Technical Field

[0001] The utility model relates to the field of vehicles, in particular to a cylinder head, an engine, a power assembly and a vehicle. Background Art

[0002] In the existing design of the engine combustion chamber, the cylinder head ridge transition surface usually affects the airflow intensity and flame diffusion speed near the cylinder head. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to provide a cylinder head. According to the cylinder head of the utility model, an arc convex toward the top is arranged at the top of the side wall and the top of the side wall is connected to the top wall, which effectively forms a uniform high-speed airflow layer at the top of the combustion chamber, further causing the airflow structure of the overall combustion chamber to be a standard "sandwich" structure, thereby improving the uniformity of flame propagation and reducing the risk of knock.

[0004] The utility model also provides an engine comprising the cylinder head.

[0005] The utility model also provides a power assembly comprising the engine.

[0006] The utility model also provides a vehicle comprising the above engine or power assembly.

[0007] According to the utility model, the cylinder head is used to enclose a combustion chamber with the piston, and the cylinder head includes a cylinder head body, and a top wall is arranged on the top of the cylinder head body; a side wall is arranged on the side of the cylinder head body, and the top edge of the side wall is constructed as an arc protruding toward the top wall and connected to the edge of the top wall, and the curvature of the arc is constant or changes continuously.

[0008] According to the cylinder head of the utility model, a top wall is arranged on the top of the cylinder head body, and side walls are arranged on both sides of the top wall in the width direction. The top edge of the side wall is connected and flush with the edge of the top wall. It can be understood that the highest point of the top of the side wall is flush with the top wall. At the same time, the curvature of the arc-shaped top edge of the side wall can be constant or continuously changed, which can prevent the upper part of the tumble flow from being retained due to the reduction in speed when passing through this part of the area. When the cylinder head and the cylinder are assembled, a combustion chamber is defined between the cylinder head and the cylinder, and the airflow entering the cylinder can form a uniform high-speed airflow layer at the top of the combustion chamber. The arc-shaped design of the side wall facilitates the flow of airflow, and can increase the speed and uniformity of the airflow entering the combustion chamber, so that the airflow structure in the combustion chamber presents a standard "sandwich" structure, thereby improving the uniformity of flame propagation in the combustion chamber and reducing the risk of cylinder knock.

[0009] According to an embodiment of the utility model, the top of the cylinder head body is provided with a first wall and a second wall, the first wall is provided with an intake valve, and the second wall is provided with an exhaust valve; the top wall is connected to the first wall and the second wall respectively.

[0010] According to an embodiment of the present invention, the first wall and the second wall extend obliquely in a direction away from each other.

[0011] According to an embodiment of the utility model, the cylinder diameter of the cylinder corresponding to the cylinder head is r, the distance between the center of the intake valve and the central axis of the cylinder head body is a1, and the following relationship is satisfied: 0.19<a1 / r<0.2.

[0012] According to an embodiment of the utility model, the cylinder diameter of the cylinder corresponding to the cylinder head is r, the distance between the center of the exhaust valve and the central axis of the cylinder head body is a2, and the following relationship is satisfied: 0.22<a2 / r<0.23.

[0013] According to an embodiment of the present utility model, the included angle between the central axis of the intake valve and the central axis of the cylinder head is α1, and satisfies: 22°<α1<23°.

[0014] According to an embodiment of the present utility model, the included angle between the central axis of the exhaust valve and the central axis of the cylinder head is α2, and satisfies: 21°<α2<22°.

[0015] According to an embodiment of the utility model, the cylinder diameter corresponding to the cylinder head is r, a base surface is formed at the bottom of the cylinder head body, a distance between the center of the intake valve and the base surface is a3, and 0.1<a3 / r<0.11 is satisfied.

[0016] According to an embodiment of the utility model, the cylinder diameter corresponding to the cylinder head is r, a base surface is formed at the bottom of the cylinder head body, a distance between the center of the exhaust valve and the base surface is a4, and 0.09<a4 / r<0.1 is satisfied.

[0017] According to an embodiment of the present utility model, the intake valve is configured as two symmetrical valves in the width direction, and the exhaust valve is configured as two symmetrical valves in the width direction.

[0018] According to one embodiment of the utility model, the top wall includes a center surface and an extension surface, and a spark plug mounting hole is formed on the center surface; the extension surfaces are arranged on both sides of the center surface in the width direction and connected to the center surface, the edges of the extension surfaces are connected to the side walls, and the extension surfaces are flush with the center surface.

[0019] According to an embodiment of the present utility model, the cylinder diameter corresponding to the cylinder head is r, the width of the piston recess is a5, and the following relationship is satisfied: 0.81<a5 / r<0.82.

[0020] The cylinder assembly according to the utility model is briefly described below.

[0021] According to the utility model, the cylinder assembly includes a piston and a cylinder head in the above embodiment. The top of the piston is formed with a piston pit corresponding to the combustion chamber defined by the cylinder head and the cylinder. It can be understood that the piston is movably arranged in the cylinder head and the cylinder, and the piston pit on the piston is directly opposite to the combustion chamber. After the cylinder head and the piston are matched, when the piston moves, the piston pit can guide the flow of air in the combustion chamber, so that the flame in the entire combustion chamber is more uniform. The setting of the cylinder head can achieve a high compression ratio in the combustion chamber of the cylinder assembly, help the flame propagation in the combustion chamber, and reduce the risk of knocking, thereby improving the performance and safety of the cylinder assembly.

[0022] According to an embodiment of the utility model, a piston pit corresponding to the combustion chamber is formed on the top of the piston, the cylinder diameter corresponding to the cylinder head is r, the width of the piston pit is a5, and satisfies: 0.81<a5 / r<0.82.

[0023] The power assembly according to the present utility model is briefly described below.

[0024] The powertrain according to the utility model includes the engine in the above-mentioned embodiment. Since the powertrain according to the utility model is provided with the engine in the above-mentioned embodiment, after the engine is assembled, the performance of the powertrain can be improved. At the same time, the knock risk of the engine itself is low, which can improve the safety and service life of the powertrain.

[0025] The vehicle according to the present utility model is briefly described below.

[0026] The vehicle according to the utility model includes the engine or powertrain in the above-mentioned embodiment. Since the vehicle according to the utility model is provided with the engine or powertrain in the above-mentioned embodiment, after the engine or powertrain is assembled with the vehicle, during the driving process of the vehicle, the engine or powertrain can improve the performance of the vehicle while avoiding knock inside the engine that affects the safety of the vehicle.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 is a structural diagram of a cylinder head according to an embodiment of the utility model;

[0030] Figure 2 is a structural diagram of a cylinder head according to an embodiment of the utility model;

[0031] Figure 3 is a top view of a cylinder head according to an embodiment of the utility model;

[0032] Figure 4 is a side view of a cylinder head according to an embodiment of the utility model;

[0033] Figure 5 is based on Figure 4 Sectional view of AA in the middle;

[0034] Figure 6 1 is a top view of a piston according to an embodiment of the utility model.

[0035] Reference numerals:

[0036] Cylinder head body 1;

[0037] A first wall 11, an air intake valve 111;

[0038] The second wall 12, the exhaust valve 121;

[0039] Top wall 13, center surface 131, spark plug mounting hole 1311, extension surface 132;

[0040] Side wall 14;

[0041] Piston 2, piston pit 21;

[0042] Positioning hole 101 and base surface 102 . DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0044] In the existing design of the engine combustion chamber, the cylinder head ridge transition surface usually affects the airflow intensity and flame diffusion speed near the cylinder head.

[0045] Reference below Figure 1-Figure 6A cylinder head according to an embodiment of the present invention is described.

[0046] According to the utility model, the cylinder head is used to enclose a combustion chamber with the piston, and the cylinder head includes a cylinder head body 1, and a top wall 13 is arranged on the top of the cylinder head body 1; a side wall 14 is arranged on the side of the cylinder head body 1, and the top edge of the side wall 14 is constructed as an arc protruding toward the top wall and connected to and flush with the edge of the top wall 13, and the curvature of the arc is unchanged or changes continuously.

[0047] According to the cylinder head of the utility model, a top wall 13 is provided on the top of the cylinder head body 1, and side walls 14 are provided on both sides of the top wall 13 in the width direction. The top edge of the side wall 14 is connected and flush with the edge of the top wall 13. It can be understood that the highest point of the top of the side wall 14 is flush with the top wall 13. At the same time, the curvature of the arc-shaped top edge of the side wall 14 can be constant or continuously changed, which can prevent the upper part of the tumble flow from being retained due to the reduction in speed when passing through this part of the area. When the cylinder head and the cylinder are assembled, a combustion chamber is defined between the cylinder head and the piston, and the airflow entering the cylinder can form a uniform high-speed airflow layer at the top of the combustion chamber. The arc-shaped design of the side wall 14 facilitates the flow of airflow, can improve the speed and uniformity of the airflow entering the combustion chamber, and make the airflow structure in the combustion chamber present a standard "sandwich" structure, thereby improving the uniformity of flame propagation in the combustion chamber and reducing the risk of cylinder knock.

[0048] According to an embodiment of the utility model, a first wall 11 and a second wall 12 are provided on the top of the cylinder head body 1. The first wall 11 is provided with an intake valve 111, and the second wall 12 is provided with an exhaust valve 121. The top wall 13 is connected to the first wall 11 and the second wall 12 respectively.

[0049] In the prior art, in the side wall on the side of the top of the cylinder head, the top edge of the side wall is constructed to be wave-like and is a certain distance away from the top wall. The design purpose of the wave shape may be to adjust the compression ratio, intake air flow and casting process to reserve or reduce the knock at the side wall position.

[0050] Therefore, the joint position between the top wall and the side wall is further away from the combustion chamber than in the flush manner, so as to reserve a certain space to form a tumble flow. However, in this embodiment, the inventors found that the tumble flow formed in this manner will be retained in the space reserved at the joint position between the side wall 14 and the top wall 13, so that the lower part of the tumble flow has a fast speed and the upper part has a slow speed. The lower part of the tumble flow has already passed the ignition area of ​​the spark plug before the spark plug ignites, resulting in a conflict between the tumble flow and the flame propagation direction, which makes it more likely to cause detonation.

[0051] It should be noted that the tumble upper part and tumble lower part referred to in the embodiments of the present application refer to the tumble formed near the top area of ​​the combustion chamber relative to the tumble center. The tumble formed near the piston head area is the tumble upper part, and the tumble formed near the piston head area is the tumble lower part.

[0052] In this embodiment, the arc-shaped design of the side wall 14 facilitates airflow, which is specifically achieved in the following manner:

[0053] After the top edge of the side wall 14 is constructed as an arc, one side of the arc corresponds to the first wall 11, and the other side of the arc corresponds to the second wall 12, that is, the arc is connected to the edges of the first wall 11 and the second wall 12 of the top wall respectively, and at the same time, the connecting part between the first wall 11 and the second wall 12 on the top wall 13 is connected to the top side of the arc; thus, the top edge of the side wall 14 is connected to the edge of the top wall 13, and the side wall 14 is flush with the top wall 13. When the cylinder head body 1 forms a combustion chamber between the piston head and the inner wall of the cylinder, the combustion chamber corresponds to the top wall 13. The part extends basically horizontally, and the upper part of the tumble flow will not be retained due to the reduction in speed when passing through this part of the area, thereby resulting in no excessively large local high-speed area in the lower part of the tumble flow. When the spark plug is ignited, the lower part of the tumble flow is in the spark plug ignition area, and the tumble flow and flame propagation directions are consistent, so detonation is not easy to occur.

[0054] According to an embodiment of the utility model, the first wall 11 and the second wall 12 extend obliquely in a direction away from each other. After assembly, the first wall 11 and the second wall 12 are arranged obliquely away from each other to improve the compactness of the cylinder head body 1 structure, and at the same time, the relative position of the intake valve 111 and the exhaust valve 121 can be changed to control the position of the tumble center.

[0055] In some embodiments, when the cylinder is inhaling, the position of the intake valve 111 will affect the position of the tumble center. For example, if the height of the intake valve 111 is higher than that of the exhaust valve 121, the tumble center will approach the position of the intake valve 111. When designing the cylinder head, the ideal state is to control the position of the tumble center so that it is located at the center of the cylinder. When the tumble center is located at the center of the cylinder, the flame can be evenly spread toward both sides of the intake valve 111 and the exhaust valve 121, reducing the risk of knock. The method of controlling the tumble center can be achieved by changing the relative positions of the intake valve 111 and the exhaust valve 121.

[0056] According to an embodiment of the utility model, the cylinder diameter corresponding to the cylinder head is r, the distance between the center of the intake valve 111 and the central axis of the cylinder head is a1, and the following conditions are satisfied: 0.19<a1 / r<0.2. During assembly, the cylinder head is matched with the corresponding cylinder. If the cylinder diameter of the cylinder is r, and the distance between the center of the intake valve 111 and the central axis of the cylinder head is a1, then 0.19<a1 / r<0.2, which can be understood as the distance between the center of the intake valve 111 and the central axis of the cylinder head is 0.19 to 0.2 times the cylinder diameter of the cylinder corresponding to the cylinder head. The center of the intake valve 111 is close to the central axis of the cylinder head, which can concentrate the tumble center in the central area of ​​the cylinder head, facilitating the propagation of the flame.

[0057] According to an embodiment of the utility model, the cylinder diameter corresponding to the cylinder head is r, the distance between the center of the exhaust valve 121 and the central axis of the cylinder head body is a2, and the following conditions are satisfied: 0.22<a2 / r<0.23. During assembly, the cylinder head is matched with the corresponding cylinder. If the cylinder diameter of the cylinder is r, and the distance between the center of the exhaust valve 121 and the central axis of the cylinder head is a2, then 0.22<a2 / r<0.23, which can be understood as the distance between the center of the exhaust valve 121 and the central axis of the cylinder head is 0.22 to 0.23 times the cylinder diameter of the cylinder corresponding to the cylinder head. The exhaust valve 121 is adjusted in conjunction with the position of the intake valve 111, so that the combustion chamber as a whole can be kept symmetrical, and the tumble center can also be concentrated in the central area of ​​the cylinder head, which is convenient for the propagation of the flame.

[0058] According to an embodiment of the utility model, the angle between the central axis of the intake valve 111 and the central axis of the cylinder head is α1, and satisfies: 22°<α1<23°. In this embodiment, the angle between the central axis of the intake valve and the central axis of the cylinder head is limited to the above range, which can limit the space between the central axis of the intake valve 111 and the central axis of the cylinder head, so that the intake valve 111 can be close to the center of the cylinder head, and then the tumble center is concentrated in the central area of ​​the cylinder head, thereby improving the uniformity of flame propagation.

[0059] According to an embodiment of the utility model, the angle between the central axis of the exhaust valve 121 and the central axis of the cylinder head is α2, and satisfies: 21°<α2<22°. During assembly, a2 limits the distance between the central axis of the exhaust valve 121 and the central axis of the cylinder head. At this time, the angle between the central axis of the exhaust valve 121 and the central axis of the cylinder head is α2, and 21°<α2<22. The setting of α2 enables the exhaust valve 121 to be adjusted in accordance with the angle α1 between the intake valve 111 and the central axis of the cylinder head, ensuring that the combustion chamber remains symmetrical as a whole.

[0060] According to an embodiment of the utility model, the cylinder diameter corresponding to the cylinder head is r, a base surface 102 is formed at the bottom of the cylinder head body 1, and the distance between the center of the intake valve 111 and the base surface 102 is a3, and 0.1<a3 / r<0.11 is satisfied. Specifically, when the cylinder head is assembled with the corresponding cylinder, a base surface 102 is formed at the bottom of the cylinder head body 1, and the distance between the center of the intake valve 111 and the base surface 102 is a3, and 0.1<a3 / r<0.11. It can be understood that the height of the center of the intake valve 111 is a3, and is 0.1 to 0.11 times the cylinder diameter of the corresponding cylinder. The setting of a3, a1 and α1 determines the position of the intake valve 111. Compared with the position of the intake valve 111 in the prior art, the relative position of the intake valve 111 in the present application is lowered, which effectively reduces the volume of the combustion chamber and provides the feasibility of a high compression ratio on the one hand; on the other hand, when approaching the top dead center, the tumble center of the airflow in the cylinder is concentrated on the central area of ​​the cylinder head, which can help the rapid development and propagation of the initial flame.

[0061] According to an embodiment of the utility model, the cylinder diameter corresponding to the cylinder head is r, a base surface 102 is formed at the bottom of the cylinder head body 1, and the distance between the center of the intake valve 111 and the base surface 102 is a4, and 0.09<a4 / r<0.1 is satisfied. Specifically, when the cylinder head is assembled with the corresponding cylinder, the distance between the center of the exhaust valve 121 and the base surface 102 is a4, and 0.09<a4 / r<0.1. It can be understood that the height of the center of the intake valve 111 is a4, and is 0.09 to 0.1 times the cylinder diameter of the corresponding cylinder. The setting of a4, a2 and α2 allows the relative position of the exhaust valve 121 to be adjusted together with the intake valve 111. Compared with the prior art, the relative position of the exhaust valve 121 of the present application is lowered, which can keep the combustion chamber design symmetrical and facilitate the propagation of the initial flame.

[0062] According to an embodiment of the utility model, the intake valve 111 and the exhaust valve 121 are respectively configured as two symmetrical valves in the width direction. The provision of the two intake valves 111 and the two exhaust valves 121 improves the efficiency of the cylinder head intake and exhaust, and at the same time enables the cylinder head and the combustion chamber formed after the cylinder head and the corresponding cylinder cooperate to have a certain degree of symmetry, which facilitates the flow of airflow and flame in the combustion chamber.

[0063] According to an embodiment of the utility model, the top wall 13 includes a center surface 131 and an extension surface 132, and the center surface 131 is formed with a spark plug mounting hole 1311; the extension surface 132 is arranged on both sides of the center surface 131 in the width direction and connected to the center surface 131, the edge of the extension surface 132 is connected to the side wall 14, and the extension surface 132 is flush with the center surface 131. Specifically, the top wall 13 is provided with a center surface 131 and an extension surface 132 connected to each other, the center surface 131 is located in the central area of ​​the cylinder head, and the extension surface 132 is constructed in two and is respectively connected to both sides of the center surface 131 in the width direction. Among them, a spark plug mounting hole 1311 is provided on the center surface 131 to facilitate the assembly of the spark plug after the cylinder head is matched with the corresponding cylinder; the extension surface 132 extends in a direction away from the center surface 131, and the end of the extension surface 132 away from the center surface 131 is connected to the side wall 14, that is, the top of the side wall 14 is flush with the extension surface 132, and at the same time, the extension surface 132 is also flush with the center surface 131. It can be understood that the top of the side wall 14 is flush with the spark plug mounting hole 1311 of the center surface 131. In addition, an extension structure can be set at the position of the spark plug mounting hole 1311, and the spark plug can be assembled into the extension structure. When the spark plug is assembled, the ceramic protective cover of the spark plug and the end face on which the spark plug is mounted are in the same plane. The spark plug mounting end face here can be understood as at least a portion of the center plane 131. The ceramic protective cover of the spark plug is flush with the end face on which the spark plug is mounted, which can reduce the obstruction of the ceramic protective cover of the spark plug to the tumble flow in the combustion chamber, thereby maintaining the strength of the airflow in the combustion chamber.

[0064] In some embodiments, a positioning hole 101 may be further provided on the extension surface 132 to facilitate assembly of the cylinder head.

[0065] The engine according to the utility model is briefly described below.

[0066] The engine according to the utility model includes a piston 2 and the cylinder head in the above embodiment. The piston 2 and the cylinder head cooperate to define a combustion chamber. The movement of the piston 2 can guide the flow of air in the combustion chamber, making the flame in the entire combustion chamber more uniform. The cylinder head body 1 includes a first wall 11, a second wall 12, an intake valve 111, and an exhaust valve 121. The arrangement of structures can achieve a high compression ratio in the combustion chamber of the engine, help the flame propagation in the combustion chamber, and reduce the risk of knocking, thereby improving the performance and safety of the engine.

[0067] According to an embodiment of the utility model, a piston pit 21 corresponding to the combustion chamber is formed on the top of the piston 2, the cylinder diameter corresponding to the cylinder head is r, the width of the piston pit 21 is a5, and it satisfies: 0.81<a5 / r<0.82. When the cylinder head is matched with the corresponding cylinder and the piston 2 is assembled, the piston pit 21 is directly opposite to the combustion chamber. When the piston 2 moves, the piston pit 21 can guide the flow of the airflow in the combustion chamber, so that the flame in the entire combustion chamber is more uniform. The width of the piston pit 21 is a5, and a5 is 0.81 to 0.82 times the cylinder diameter. In addition, the distance between the center of the piston pit 21 and the spark plug mounting end face can be 0.17 to 0.18 times the cylinder diameter; the length of the piston pit 21 can be 0.48 to 0.49 times the cylinder diameter. The size design of the piston pit 21 is that the fire pit presents a geometric surface similar to an "American football". Compared with the piston pit 21 in the prior art, the piston pit 21 of the present application can help maintain the airflow intensity close to the surface of the piston pit 21 when the piston 2 moves upward, thereby increasing the propagation speed of the initial flame.

[0068] In some embodiments, the cylinder head is provided with a squeeze area on the side of the exhaust valve 121 away from the intake valve 111 and between the two exhaust valves 121. The squeeze area can cooperate with the corresponding position on the piston pit 21. At a position near the top dead center, the squeeze area generates a squeeze flow and protects the tumble center in the cylinder, thereby maintaining the airflow intensity near the initial flame.

[0069] The power assembly according to the present utility model is briefly described below.

[0070] The powertrain according to the utility model includes the engine in the above-mentioned embodiment. Since the powertrain according to the utility model is provided with the engine in the above-mentioned embodiment, after the engine is assembled, the performance of the powertrain can be improved. At the same time, the knock risk of the engine itself is low, which can improve the safety and service life of the powertrain.

[0071] The vehicle according to the present utility model is briefly described below.

[0072] The vehicle according to the utility model includes the engine or powertrain in the above-mentioned embodiment. Since the vehicle according to the utility model is provided with the engine or powertrain in the above-mentioned embodiment, after the engine or powertrain is assembled with the vehicle, during the driving process of the vehicle, the engine or powertrain can improve the performance of the vehicle while avoiding knock inside the engine that affects the safety of the vehicle.

[0073] In the description of the present invention, 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", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 invention.

[0074] In the description of the present invention, "first feature" or "second feature" may include one or more of the features.

[0075] In the description of the present invention, "plurality" means two or more.

[0076] In the description of the present invention, a first feature being “above” or “below” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact but are in contact with each other via another feature therebetween.

[0077] In the description of the present invention, a first feature “above”, “over” and “above” a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0078] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0079] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A cylinder head, used to enclose a combustion chamber with a piston, characterized in that: include: A cylinder head body, wherein a top wall is arranged on the top of the cylinder head body; A side wall is provided on the side of the cylinder head body, and the top edge of the side wall is configured as an arc convex toward the top wall and connected to the edge of the top wall, and the curvature of the arc is constant or changes continuously.

2. The cylinder head according to claim 1, characterized in that: The top of the cylinder head body is provided with a first wall and a second wall, the first wall is provided with an intake valve, and the second wall is provided with an exhaust valve; The top wall is connected to the first wall and the second wall respectively.

3. The cylinder head according to claim 2, characterized in that: The first wall and the second wall extend obliquely in a direction away from each other.

4. The cylinder head according to claim 3, characterized in that: The cylinder diameter of the cylinder corresponding to the cylinder head is r, the distance between the center of the intake valve and the central axis of the cylinder head body is a1, and the following relationship is satisfied: 0.19<a1 / r<0.

2.

5. The cylinder head according to claim 3, characterized in that: The cylinder diameter of the cylinder corresponding to the cylinder head is r, the distance between the center of the exhaust valve and the central axis of the cylinder head body is a2, and the following relationship is satisfied: 0.22<a2 / r<0.

23.

6. The cylinder head according to claim 3, characterized in that: The included angle between the central axis of the intake valve and the central axis of the cylinder head is α1, and satisfies: 22°<α1<23°.

7. The cylinder head according to claim 3, characterized in that: The included angle between the central axis of the exhaust valve and the central axis of the cylinder head is α2, and satisfies: 21°<α2<22°.

8. The cylinder head according to claim 2, characterized in that: The cylinder diameter of the cylinder corresponding to the cylinder head is r, a base surface is formed at the bottom of the cylinder head body, a distance between the center of the intake valve and the base surface is a3, and 0.1<a3 / r<0.11 is satisfied.

9. The cylinder head according to claim 2 or 8, characterized in that: The cylinder diameter of the cylinder corresponding to the cylinder head is r, a base surface is formed at the bottom of the cylinder head body, a distance between the center of the exhaust valve and the base surface is a4, and 0.09<a4 / r<0.1 is satisfied.

10. The cylinder head according to claim 2, characterized in that The intake valves are configured as two symmetrical valves in the width direction, and the exhaust valves are configured as two symmetrical valves in the width direction.

11. The cylinder head according to claim 1, characterized in that The top wall comprises: A center surface, wherein a spark plug mounting hole is formed on the center surface; The extension surface is arranged on both sides of the central surface in the width direction and connected to the central surface, the edge of the extension surface is connected to the side wall, and the extension surface is flush with the central surface.

12. An engine, characterized in that: include: A cylinder head, wherein the cylinder head is constructed as the cylinder head according to any one of claims 1 to 11; A piston is engaged with the cylinder head.

13. The engine according to claim 12, characterized in that A piston recess corresponding to the combustion chamber is formed on the top of the piston, the cylinder diameter corresponding to the cylinder head is r, the width of the piston recess is a5, and the following relationship is satisfied: 0.81<a5 / r<0.

82.

14. A powertrain, characterized in that: An engine comprising any one of claims 12-13.

15. A vehicle, characterized in that: include: An engine, wherein the engine structure is the engine described in any one of 12-13; or A powertrain, wherein the powertrain is configured as the powertrain as claimed in claim 14.

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