A cylinder head and cylinder head assembly

Abstract

The present application provides a cylinder head, which relates to the field of vehicles, and comprises a cover body, in a first direction, a middle region of the cover body is provided with an oil injector mounting hole and an igniter mounting hole at intervals; in a second direction, the cover body is further provided with an intake valve mounting hole and an exhaust valve mounting hole at intervals, and the intake valve mounting hole and the exhaust valve mounting hole are respectively located on two sides of the middle region, and the second direction is perpendicular to the first direction; in the second direction, at least one side of the middle region has a compression structure which protrudes from a bottom surface of the cover body. The present application further provides a cylinder head assembly, and the cylinder head and the cylinder head assembly can improve the combustion efficiency of a compression ignition engine.

Description

Technical Field

[0001] This invention relates to the field of vehicles, and more particularly to a cylinder head and cylinder head assembly. Background Technology

[0002] Hybrid vehicles or pure gasoline-powered vehicles all have at least one internal combustion engine. An internal combustion engine is a device that converts the internal energy of fuel into the kinetic energy of a piston by forcing fuel into a cylinder and violently burning the fuel-air mixture inside. Some engine types are equipped with spark plugs, which provide ignition energy to ignite at least a portion of the air-fuel mixture entering the cylinder, according to the required combustion mode. Inappropriate combustion chamber design in some engines leads to low combustion efficiency. Summary of the Invention

[0003] This invention provides a cylinder head and cylinder head assembly for solving the problem of how to make the fuel and air in an engine more fully mixed, thereby improving the combustion efficiency of the engine.

[0004] This invention provides a cylinder head, comprising: a cover body, wherein in a first direction, a central region of the cover body is provided with an injector mounting hole and an ignition mounting hole spaced apart; along a second direction, the cover body is also provided with an intake valve mounting hole and an exhaust valve mounting hole spaced apart, wherein the intake valve mounting hole and the exhaust valve mounting hole are respectively located on both sides of the central region, and the second direction is perpendicular to the first direction; along the second direction, at least one side of the central region has a compression structure protruding from the bottom surface of the cover body.

[0005] Furthermore, the air compression structure is located on the side of the central region where the intake valve mounting hole is provided.

[0006] Furthermore, the compressed air structure includes:

[0007] A compressor boss surrounds the intake valve mounting hole and protrudes from the bottom surface of the cover; a guide boss is located along the second direction between the compressor boss and the bottom surface of the central region; wherein the bottom surface of the guide boss connects the bottom surface of the central region and the bottom surface of the compressor boss, and the bottom surface of the guide boss and the bottom surface of the compressor boss are smoothly transitioned by a curved surface.

[0008] Furthermore, the bottom of the cover has an air intake side extrusion surface. In the second direction, the air intake side extrusion surface is located on the edge of the cover on the side where the air intake door mounting hole is provided, and the air intake side extrusion surface is tangent to the bottom surface of the air pressure boss and the bottom surface of the cover, respectively.

[0009] Furthermore, in the second direction, the bottom surface of the cover body on the side where the exhaust valve mounting hole is provided is provided with an exhaust air guiding surface; in the thickness direction of the cover body, the distance between the side of the exhaust air guiding surface near the central region and the bottom surface of the central region is less than the distance between the side of the exhaust air guiding surface away from the central region and the bottom surface of the central region.

[0010] Furthermore, the bottom of the cover also has an exhaust-side extrusion surface. In the second direction, the exhaust-side extrusion surface is located on the edge of the cover on the side where the exhaust door mounting hole is provided, and the exhaust-side extrusion surface is tangent to the exhaust guide surface and the bottom surface of the cover, respectively.

[0011] Furthermore, both the intake valve mounting hole and the exhaust valve mounting hole are provided in pairs. The two intake valve mounting holes are spaced apart on both sides of the central region along the first direction, and the two exhaust valve mounting holes are spaced apart on both sides of the central region along the first direction.

[0012] Furthermore, the bottom of the cylinder head also has two central extrusion surfaces. Along the first direction, the two central extrusion surfaces are respectively located between the intake valve mounting hole and the exhaust valve mounting hole on the same side; the two central extrusion surfaces are tangent to the air compression structure and the exhaust air guide surface, respectively.

[0013] This invention also provides a cylinder head assembly, which includes: a cylinder head as described above; an intake valve, at least partially located within the intake valve mounting hole; wherein the bottom surface of the cylinder head has a compressor boss, the compressor boss surrounding the intake valve mounting hole, and in the initial position of the intake valve, the bottom surface of the compressor boss is located below the bottom surface of the intake valve.

[0014] Furthermore, the cylinder head assembly also includes an exhaust valve located within the exhaust valve mounting hole; wherein the bottom surface of the cylinder head also has an exhaust guide surface, and in the initial position of the exhaust valve, at least a portion of the bottom surface of the exhaust valve is located below the exhaust guide surface.

[0015] This invention provides a cylinder head, which includes: a cover body having injector mounting holes and ignition mounting holes spaced apart along a first direction in a central region; and an intake valve mounting hole and an exhaust valve mounting hole spaced apart along a second direction, wherein the intake valve mounting holes and exhaust valve mounting holes are located on both sides of the central region, and the second direction is perpendicular to the first direction. Simultaneously, along the second direction, at least one side of the central region is provided with a compressor structure protruding from the bottom surface of the cover. By providing a compressor structure protruding from the bottom surface of the cover, the volume of the engine combustion chamber is reduced, and the ratio of the engine combustion chamber volume to the total cylinder volume is reduced, thereby increasing the engine compression ratio. This makes it easier for the ignition-compression ignition engine to simultaneously compress and ignite the lean air-fuel mixture surrounding the flame core during the compression stage. At the same time, by setting the compressor structure on the side of the central region, the possibility of assembly interference between the compressor structure and the injector and igniter is reduced, as is the possibility of the compressor structure blocking the flame propagation path during combustion. This improves the engine's combustion efficiency. In other words, by providing a compressor structure on the side of the central region of the cylinder head bottom, the shape of the engine's combustion chamber is optimized, making the combustion chamber shape more suitable for ignition-compression ignition engines, thereby improving the combustion efficiency of ignition-compression ignition engines. Attached Figure Description

[0016] Figure 1 A schematic diagram of a cylinder head structure provided in an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of another cylinder head structure provided in an embodiment of the present invention;

[0018] Figure 3 for Figure 2 A magnified view of part A in the middle;

[0019] Figure 4 This is a schematic diagram showing the positional relationship between the intake valve, exhaust valve, and cylinder head in a cylinder head assembly provided in an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures

[0021] 10. Cylinder head; 20. Intake valve; 30. Exhaust valve; 100. Cover body; 110. Injector mounting hole; 120. Ignition valve mounting hole; 130. Intake valve mounting hole; 140. Exhaust valve mounting hole; 150. Compressor structure; 151. Air guide boss; 152. Compressor boss; 153. First arc surface; 154. Second arc surface; 155. Intake side extrusion surface; 160. Exhaust air guide surface; 161. Exhaust side extrusion surface; 170. Middle extrusion surface. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] The specific technical features described in the specific embodiments can be combined in any suitable manner without contradiction. For example, different combinations of specific technical features can form different embodiments and technical solutions. To avoid unnecessary repetition, the various possible combinations of the specific technical features in this invention will not be described separately.

[0024] In the following description, the terms "first," "second," etc., are used merely to distinguish different objects and do not indicate that the objects have the sameness or relationship. It should be understood that the directional descriptions "above," "below," "outside," and "inside" refer to the orientation under normal use conditions, while "left" and "right" refer to the left and right directions shown in the corresponding diagrams, which may or may not be the left and right directions under normal use conditions.

[0025] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. The term "connection," unless otherwise specified, includes both direct and indirect connections.

[0026] The cylinder head provided in the following specific embodiments can be applied to engines of any vehicle type. For example, the cylinder head can be applied to the engine of a passenger car, and for example, the cylinder head can also be applied to the engine of a truck.

[0027] In some embodiments, such as Figure 1 As shown, the cylinder head 10 includes a cover body 100, the cover body 100 being along a first direction (the first direction is as follows). Figure 1The central area (as indicated by the solid arrow) is provided with injector mounting holes 110 and ignition mounting holes 120 at intervals. Injector mounting holes 110 are used to mount injectors, and ignition mounting holes 120 are used to mount ignition devices. In a compression ignition engine, the injector needs to perform two injections. The first injection occurs during the intake stroke to form a lean air-fuel mixture in the engine cylinder. That is, the injector injects a small amount of fuel into the cylinder during the intake stroke, which mixes with a small amount of combustion air flowing into the cylinder through the intake manifold, thus forming a low-concentration air-fuel mixture in the cylinder. The second injection... Secondary fuel injection occurs during the compression stroke. Fuel is injected into the central recess on the piston crown when the piston reaches a preset height, thereby forming a locally enriched air-fuel mixture in the central recess. As the piston continues to move to near top dead center, the engine's ignition device ignites the locally enriched air-fuel mixture in the central recess, forming a flame core. This flame core heats the lean air-fuel mixture surrounding it, and the piston continues to compress the lean air-fuel mixture, causing it to be ignited under the combined action of the flame core's heating and the piston's compression. This can be understood as follows: the injector of a compression ignition engine needs to inject fuel into the middle of the cylinder, while the igniter needs to ignite the locally enriched fuel-air mixture formed by the second fuel injection in the central recess of the piston. By placing the injector mounting hole 110 and the igniter mounting hole 120 in the middle region of the cylinder head, the distance between the position of the injector and the igniter and the middle of the cylinder can be reduced, thereby reducing the tilt angle of the injector and the igniter, and thus reducing the difficulty of installing the injector into the injector mounting hole 110 and the igniter into the igniter mounting hole 120.

[0028] Along the second direction (the second direction is as follows) Figure 1 (As indicated by the dashed arrow) The cover 100 is also provided with intake valve mounting holes 130 and exhaust valve mounting holes 140 at intervals, and the intake valve mounting holes 130 and exhaust valve mounting holes 140 are located on both sides of the central region, with the second direction perpendicular to the first direction. The intake valve mounting hole 130 is used to install the intake valve, and the engine's intake pipe communicates with the engine cylinder through the intake valve mounting hole 130. During the intake stroke and exhaust stroke, the intake valve opens the intake valve mounting hole 130 to allow outside air to enter the engine cylinder through the intake pipe and the intake valve mounting hole 130. During the exhaust stroke, the exhaust valve opens the exhaust valve mounting hole 140 to allow the combustion exhaust gas in the cylinder to be discharged from the engine cylinder through the exhaust valve mounting hole 140. For ease of explanation, the side of the cover 100 with the intake valve mounting hole 130 in the second direction will be referred to as the intake side, and the side of the cover 100 with the exhaust valve mounting hole 140 in the second direction will be referred to as the exhaust side.

[0029] Along the second direction, at least one side of the central region has a compressed air structure 150 protruding from the bottom surface of the cover 100, wherein, in the operating state of the engine, the cover 100 is connected to the cylinder block of the engine, and the bottom surface of the cover 100 covers the top opening of the cylinder in the cylinder block, that is, the surface of the cover 100 used to cover the top opening of the cylinder is the bottom surface of the cover 100. In the second direction, the surface of the cover 100 for sealing the top opening of the cylinder is provided with a compression structure extending into the cylinder. This can be understood as the compression structure 150 being disposed on the intake and / or exhaust side of the cover 100. The outer surface of the compression structure 150 adjacent to the cylinder, the bottom surface of the cover 100, the top surface of the piston, and part of the sidewall of the cylinder surround and form the combustion chamber of the engine. The outer surface of the compression structure 150 adjacent to the cylinder and the bottom surface of the cover 100 form the top surface of this combustion chamber. This is achieved by providing a compression structure protruding from the bottom surface of the cover 100. The compression ratio 150 is reduced, decreasing the ratio of the combustion chamber volume to the total cylinder volume. This increases the compression ratio of the ignition engine, making it easier for the ignition compression ignition engine to synchronously ignite the lean air-fuel mixture in the cylinder, thus improving the combustion efficiency of the ignition compression ignition engine. At the same time, placing the compressor structure 150 on the side of the central region reduces the possibility of assembly interference between the compressor structure 150 and the igniter and injector. It also reduces the possibility of the compressor structure 150 blocking the flame propagation path during combustion, further increasing the combustion efficiency of the ignition compression ignition engine.

[0030] This invention provides a cylinder head, which includes: a cover body having injector mounting holes and ignition mounting holes spaced apart along a first direction in a central region; and an intake valve mounting hole and an exhaust valve mounting hole spaced apart along a second direction, wherein the intake valve mounting holes and exhaust valve mounting holes are located on both sides of the central region, and the second direction is perpendicular to the first direction. Simultaneously, along the second direction, at least one side of the central region is provided with a compressor structure protruding from the bottom surface of the cover. By providing a compressor structure protruding from the bottom surface of the cover, the volume of the engine combustion chamber is reduced, and the ratio of the engine combustion chamber volume to the total cylinder volume is reduced, thereby increasing the engine compression ratio. This makes it easier for the ignition-compression ignition engine to simultaneously compress and ignite the lean air-fuel mixture surrounding the flame core during the compression stage. At the same time, by setting the compressor structure on the side of the central region, the possibility of assembly interference between the compressor structure and the injector and igniter is reduced, as is the possibility of the compressor structure blocking the flame propagation path during combustion. This improves the engine's combustion efficiency. In other words, by providing a compressor structure on the side of the central region of the cylinder head bottom, the shape of the engine's combustion chamber is optimized, making the combustion chamber shape more suitable for ignition-compression ignition engines, thereby improving the combustion efficiency of ignition-compression ignition engines.

[0031] In some embodiments, such as Figure 1As shown, the air compressor structure 150 is located on the bottom surface of the cover 100 on the side where the intake valve mounting hole 130 is provided. That is, the air compressor structure 150 is located on the intake side of the cylinder head 10. By setting the air compressor structure 150 on the intake side, it is possible to compress and ignite the lean air-fuel mixture during the combustion process of the engine, while pushing the flame and combustion exhaust gas towards the exhaust side, so that the exhaust gas generated after combustion is closer to the exhaust valve mounting hole 140. This allows the combustion exhaust gas in the cylinder to be discharged more fully during the exhaust process, reducing the intake back pressure of the engine and further improving the combustion efficiency of the engine. It should be noted that, in the direction perpendicular to the bottom surface of the cylinder block 100, the dimension of the air compression structure 150 protruding from the bottom surface of the cylinder block 100 is less than a preset depth threshold. This ensures that during engine combustion, the pressure difference between the intake and exhaust sides of the combustion chamber is less than the preset threshold, so that the lean air-fuel mixture on the intake side of the combustion chamber will not be ignited by compression before the lean air-fuel mixture on the exhaust side due to this pressure difference. At the same time, it prevents the piston from wobbling excessively under the action of this pressure difference, and prevents knocking phenomenon from occurring under the action of this wobbling.

[0032] In some embodiments, such as Figure 2 As shown, the air compressor structure 150 includes a compressor boss 152 and a guide boss 151. The compressor boss 152 surrounds the intake valve mounting hole 130 and protrudes from the bottom surface of the cover 100. That is, the compressor boss 152 is used to compress the lean fuel mixture on the intake side during engine combustion, thereby increasing the engine's compression ratio. Simultaneously, by surrounding the intake valve mounting hole 130 with the compressor boss 152, the bottom surface volume on the intake side of the cover 100 is fully utilized. Furthermore, the sidewall of the compressor boss 152 surrounding the intake valve mounting hole 130 serves as a guide surface for the intake passage, extending the length of the guide passage and allowing air to flow for a longer time within it. This results in the air entering the cylinder having a more precise direction. The higher speed allows the air to form a stronger, predetermined airflow within the cylinder. For example, when the intake manifold is a spirally coiled vortex manifold, the sidewall of the compressor boss 130 surrounding the intake valve mounting hole 130 can prolong the time the air flows within the spiral intake passage. This allows the air to accelerate along the spiral intake passage for a longer period, thereby forming a stronger vortex airflow within the cylinder. This also allows the air entering the cylinder to mix more thoroughly with the combustion air entering the cylinder during the first fuel injection, forming a lean fuel-air mixture with a more uniform concentration distribution, further improving the combustion efficiency of the compression ignition engine.

[0033] Along the second direction, the air guide boss 151 is located between the compressor boss 152 and the bottom surface of the central region of the cover 100, serving to connect the bottom surface of the central region of the cover 100 and the compressor boss 152. The bottom surface of the air guide boss 151 connects the bottom surface of the compressor boss 152 and the bottom surface of the central region of the cover 100. The air guide boss 151 smoothly connects the bottom surface of the central region of the cover 100 and the bottom surface of the compressor boss 152, thereby reducing the impact of the first airflow during the engine's intake and compression strokes. During the first injection, the air resistance between the bottom surface of the fuel entering the cylinder and the air entering the engine in the central region and the compressor boss 152 increases, resulting in a more uniform fuel-air mixture. Simultaneously, during combustion, the air guide boss 151 reduces the flow resistance of the flame within the combustion chamber, allowing the flame to spread more smoothly throughout the entire combustion chamber. This results in higher combustion synchronicity of the lean air-fuel mixture surrounding the flame core within the combustion chamber, further improving the combustion efficiency of the compression ignition engine. Furthermore, the bottom surface of the air guide boss 151 and the bottom surface of the compressor boss 152 are smoothly transitioned by a curved surface. This can be understood as a curved surface being provided between the bottom surfaces of the air guide boss 151 and the compressor boss 152, such that this curved surface is tangent to both the bottom surfaces of the air guide boss 151 and the compressor boss 152. For example, as shown... Figure 3 As shown, the curved surface includes a first arc surface 153 and a second arc surface 154. The first arc surface 153 is tangent to the bottom surface of the compressor boss 152, and the center of the first arc surface 153 points outwards from the combustion chamber. One side of the second arc surface 154 is tangent to the first arc surface, and the other side of the second arc surface 154 is tangent to the bottom surface of the middle region of the cover 100. The center of the second arc surface 153 points inwards from the interior of the combustion chamber. The radii of both the first arc surface 153 and the second arc surface 154 are 3 mm.

[0034] In some embodiments, such as Figure 2 As shown, the bottom of the cover 100 has an intake-side extrusion surface 155. In the second direction, the intake-side extrusion surface 155 is located at the edge of the intake side of the cover 100, and the intake-side extrusion surface 155 is tangent to the bottom surface of the compressor boss 152 and the bottom surface of the cover 100, respectively. It can be understood that an intake-side intake surface 155 is provided at the edge of the intake side of the cover 100 to smoothly connect the compressor boss 152 and the bottom surface of the cover 100 into one unit, further reducing the flame propagation resistance of the piston at the edge of the intake side of the cover 100, and further improving the combustion efficiency of the engine.

[0035] In some embodiments, such as Figure 2As shown, in the second direction, an exhaust guide surface 160 is provided on the bottom surface of the cover 100 on the side where the exhaust valve mounting hole 130 is provided. That is, in the second direction, the guide surface 160 and the compression structure 150 are located on both sides of the bottom surface of the central region of the cover. In the thickness direction of the cover 100, the distance between the side of the exhaust guide surface 160 near the central region and the bottom surface of the central region is smaller than the distance between the side of the exhaust guide surface away from the central region and the bottom surface of the central region. This results in the volume of the combustion chamber on the exhaust side of the engine near the bottom surface of the central region of the cover 100 being smaller than the volume of the bottom surface of the central region of the cover 100. As a result, after combustion, the portion of the combustion chamber on the exhaust side away from the central region can accommodate more combustion exhaust gas. The exhaust valve mounting hole 150 is provided in this region, and the combustion exhaust gas generated after combustion can be more easily discharged from the cylinder, further improving the combustion efficiency of the engine. Optionally, the bottom surface of the air guide surface 160 is an inclined slope, thereby further reducing the propagation resistance of the flame and combustion exhaust gas in the combustion chamber and further improving the combustion efficiency of the engine. Optionally, a transition curved surface is provided between the bottom surfaces of the air guide surface 160 and the bottom surfaces of the middle region of the cover 100 to smoothly connect the bottom surfaces of the air guide surface 160 and the bottom surfaces of the middle region of the cover 100, thereby further reducing the propagation resistance of the flame and combustion exhaust gas in the combustion chamber and further improving the combustion efficiency of the engine.

[0036] In some embodiments, such as Figure 2 As shown, the bottom of the cover 100 also has an exhaust-side extrusion surface 161. In the second direction, the exhaust-side extrusion surface 161 is located at the edge of the air intake side of the cover 100, and the exhaust-side extrusion surface 161 is tangent to the bottom surface of the exhaust guide surface 160 and the bottom surface of the cover 100, respectively. It can be understood that the exhaust-side extrusion surface 161 is provided at the edge of the air intake side of the cover 100 to smoothly connect the exhaust guide surface 160 and the bottom surface of the cover 100 into one unit, further reducing the flame propagation resistance of the piston at the edge of the air intake side of the cover 100, and further improving the combustion efficiency of the engine.

[0037] In some embodiments, such as Figure 2As shown, there are two intake valve mounting holes 130 and two exhaust valve mounting holes 140. The two intake valve mounting holes 130 are spaced apart on both sides of the central region along the first direction, and the two exhaust valve mounting holes 140 are spaced apart on both sides of the central region along the first direction. Specifically, on the intake side, the two intake valve mounting holes 120 are spaced apart on both sides of the central region of the cover 100 where the injector mounting hole 110 and the igniter mounting hole 120 are located along the first direction. On the exhaust side, the two exhaust valve mounting holes 130 are spaced apart on both sides of the central region of the cover 100 where the injector mounting hole 110 and the igniter mounting hole 120 are located along the first direction. This reduces the possibility of interference between the intake valve mounting holes 130 and the exhaust valve mounting holes 140 and the injector and igniter, while making full use of the volume of the cover to increase the size of the engine's intake and exhaust ports, thereby making the engine's intake and exhaust more complete and further improving the engine's combustion efficiency.

[0038] In some embodiments, such as Figure 2 As shown, the bottom of the cover 100 also has two central extrusion surfaces 170. Along the first direction, the two central extrusion surfaces 170 are located between the intake valve mounting hole 130 and the exhaust valve mounting hole 140 on the same side. For ease of explanation, the first side of the engine is referred to as the front end of the engine and the other side as the rear end of the engine. One central extrusion surface 170 is located between the intake valve mounting hole 130 and the exhaust valve mounting hole 140 at the front end of the engine, and the other central extrusion surface 170 is located between the intake valve mounting hole 130 and the exhaust valve mounting hole 140 at the rear end of the engine. The two central extrusion surfaces 170 are tangent to the compressor structure 150 and the exhaust guide surface 160, respectively. That is, the two central extrusion surfaces 170 smoothly connect the portion of the compressor structure 150 surrounding the intake valve mounting hole 130 and the portion of the compressor structure 170 surrounding the exhaust valve mounting hole 140, thereby further reducing the resistance to flame propagation in the combustion chamber of the engine and improving the combustion efficiency of the engine.

[0039] This invention also provides a cylinder head assembly for an ignition compression ignition engine. After being connected to the engine block, the cylinder head assembly can seal the opening at the top of the cylinder inside the cylinder head, control the time when air enters the cylinder, inject combustion into the cylinder, and ignite at least a portion of the combustion in the cylinder.

[0040] In some embodiments, such as Figure 4 As shown, cylinder head assembly 1 includes: as above Figures 1 to 3The cylinder head 10 and intake valve 20 are shown in any of the accompanying drawings in the instruction manual. At least a portion of the intake valve 20 is located within the intake valve mounting hole 130 for controlling the timing of external air entering the cylinder block. The bottom surface of the cylinder head 10 has a compressor boss 152 surrounding the intake valve mounting hole, with the bottom surface of the compressor boss 152 located below the bottom surface of the intake valve when the intake valve 20 is in its initial position. Specifically, the intake valve 20 can move between a first position and a second position under the action of the pushrod or valve cam. When intake is not required, the intake valve is in the first position, and the intake valve 20 blocks the intake valve mounting hole 130. At this time, the air-fuel mixture in the engine cannot leak to the outside of the cylinder through the intake valve mounting hole 20. When intake is required, the intake valve moves downward from the first position to the second position, and the intake valve 20 opens the intake valve mounting hole 130, allowing air from outside the engine to enter the cylinder through the intake valve mounting hole 130. The initial position of the intake valve 20 is this first position. By setting the first position of the intake valve 120 above the bottom surface of the compressor boss 152, during the opening of the intake valve 20, the inner wall of the portion of the compressor boss 152 surrounding the intake valve mounting hole 130 forms an intake guide surface, thereby enhancing the intensity of the airflow entering the cylinder and further improving the combustion efficiency of the engine. Optionally, such as Figure 4 As shown, the bottom surface of the cylinder head 10 also has a guide boss 151. The bottom surface of the guide boss 151 is connected to the bottom surface of the compressor boss 152 and the bottom surface of the cylinder head 10. When the intake valve 20 is in the initial position, the bottom surface of the guide boss 151 is located above the bottom surface of the intake valve, thereby reducing intake resistance and increasing the intake volume of the engine.

[0041] In some embodiments, such as Figure 4As shown, the cylinder head assembly 1 also includes an exhaust valve 30. The exhaust valve is located within the exhaust valve mounting hole 140 and is used to control the exhaust timing of the engine. The bottom surface of the cylinder head 10 also has an exhaust guide surface 160. When the exhaust valve is in its initial position, at least a portion of the bottom surface of the exhaust valve 30 is located below the exhaust guide surface 160. Specifically, the exhaust valve 30 can move between a third position and a fourth position under the action of a pushrod or valve cam. When exhaust is not required, the exhaust valve 30 is in the third position, blocking the exhaust valve mounting hole 140. At this time, the fuel-air mixture in the engine cannot leak to the outside of the cylinder through the exhaust valve mounting hole 140. When exhaust is required, the exhaust valve 30 moves downward from the third position to the fourth position, opening the exhaust valve mounting hole 140, allowing the combustion exhaust gas in the cylinder to be discharged from the cylinder through the exhaust valve mounting hole 140. The initial position of the exhaust valve 30 is the third position. By placing at least a portion of the bottom surface of the exhaust valve 30 below the bottom surface of the exhaust guide surface 160, the possibility of the exhaust guide surface 160 affecting the exhaust is reduced, and the exhaust gas in the cylinder is more easily discharged out of the cylinder, making the exhaust of the engine more complete and further improving the combustion efficiency of the engine.

[0042] The cylinder head assembly 1 also includes an injector installed in the injector mounting hole 110 and an igniter installed in the igniter mounting hole 120. The injector needs to perform two injections. The first injection occurs during the intake stroke to form a lean air-fuel mixture in the cylinder. That is, the injector injects a small amount of fuel into the cylinder during the intake stroke, which mixes with the air entering the cylinder from the intake manifold to form a low-concentration air-fuel mixture. The second injection occurs during the compression stroke, where fuel is injected into the central recess on the piston crown when the piston reaches a preset height, thereby forming a locally enriched air-fuel mixture in the central recess on the piston crown. When the piston continues to move to near top dead center, the engine's ignition device ignites the locally enriched air-fuel mixture in the central recess, forming a flame core. The flame core heats the lean air-fuel mixture around the flame core, and the piston continues to compress the lean air-fuel mixture, causing the surrounding lean air-fuel mixture to be ignited under the combined action of the flame core's heating and the piston's compression.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A cylinder head, characterized in that, Applied to a spark-compression ignition engine with a spiral intake passage; the cylinder head includes: In the first direction, the cover body has fuel injector mounting holes and igniter mounting holes spaced apart in the middle region of the cover body; The cover is also provided with an intake valve mounting hole and an exhaust valve mounting hole at intervals along the second direction, and the intake valve mounting hole and the exhaust valve mounting hole are respectively located on both sides of the central region, and the second direction is perpendicular to the first direction; Along the second direction, at least one side of the central region has a compressive structure protruding from the bottom surface of the cover; the compressive structure includes a compressive boss and a guide boss; the compressive boss surrounds the intake valve mounting hole and protrudes from the bottom surface of the cover; the sidewall of the compressive boss prolongs the time for air to flow within the spiral intake channel; along the second direction, the guide boss is located between the compressive boss and the bottom surface of the central region; the bottom surface of the guide boss connects the bottom surface of the central region and the bottom surface of the compressive boss, thus smoothly connecting the bottom surface of the central region of the cover and the bottom surface of the compressive boss through the guide boss.

2. The cylinder head according to claim 1, characterized in that, The air compression structure is located on the side of the central region where the intake valve mounting hole is provided.

3. The cylinder head according to claim 2, characterized in that, The bottom surface of the air guide boss and the bottom surface of the air compressor boss are smoothly transitioned by a curved surface.

4. The cylinder head according to claim 3, characterized in that, The bottom of the cover has an air intake side extrusion surface. In the second direction, the air intake side extrusion surface is located on the edge of the cover on the side where the air intake door mounting hole is provided, and the air intake side extrusion surface is tangent to the bottom surface of the air pressure boss and the bottom surface of the cover, respectively.

5. The cylinder head according to claim 2, characterized in that, In the second direction, the bottom surface of the cover on the side where the exhaust valve mounting hole is located is provided with an exhaust air guide surface.

6. The cylinder head according to claim 5, characterized in that, The bottom of the cover also has an exhaust-side extrusion surface. In the second direction, the exhaust-side extrusion surface is located on the edge of the cover on the side where the exhaust door mounting hole is provided, and the exhaust-side extrusion surface is tangent to the exhaust guide surface and the bottom surface of the cover, respectively.

7. The cylinder head according to claim 5, characterized in that, There are two intake valve mounting holes and two exhaust valve mounting holes. The two intake valve mounting holes are spaced apart on both sides of the central region along the first direction, and the two exhaust valve mounting holes are spaced apart on both sides of the central region along the first direction.

8. The cylinder head according to claim 7, characterized in that, The bottom of the cylinder head also has two central extrusion surfaces, and along the first direction, the two central extrusion surfaces are respectively located between the intake valve mounting hole and the exhaust valve mounting hole on the same side; The two central extrusion surfaces are tangent to the air compression structure and the exhaust air guide surface, respectively.

9. A cylinder head assembly, characterized in that, The cylinder head assembly includes: Cylinder head as described in any one of claims 1 to 8; The intake valve is at least partially located within the intake valve mounting hole; The cylinder head has a compressor boss on its bottom surface, which surrounds the intake valve mounting hole. When the intake valve is in its initial position, the bottom surface of the compressor boss is located below the bottom surface of the intake valve.

10. The cylinder head assembly according to claim 9, characterized in that, The cylinder head assembly also includes: The exhaust valve is located within the exhaust valve mounting hole; The cylinder head also has an exhaust guide surface on its bottom surface, and when the exhaust valve is in its initial position, at least a portion of the bottom surface of the exhaust valve is located below the exhaust guide surface.

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