engine

Abstract

The application provides an engine, which comprises a cylinder head, a cylinder body and an air intake system; the cylinder head is provided with an air inlet channel and an exhaust channel; the cylinder body is connected with the cylinder head and forms a combustion chamber with the cylinder head, and the combustion chamber is communicated with the air inlet channel and the exhaust channel; the air intake system comprises a throttle valve connected with the cylinder head, and the throttle valve is communicated with the air inlet channel; the cylinder head comprises a plurality of mounting portions, the plurality of mounting portions are tightly connected with the throttle valve through fasteners, the plurality of mounting portions are provided with end faces abutting against the throttle valve, the plurality of mounting portions comprise a first mounting portion and a second mounting portion, the first mounting portion is located above the second mounting portion, and the end face of the first mounting portion is parallel to and does not coincide with the end face of the second mounting portion. Through the above arrangement, the overall structural strength of the cylinder head is higher, the mode is better, the overall structure of the cylinder head is more compact, and the lightweight design of the engine is facilitated.

Description

Technical Field

[0001] This application relates to the field of power systems, and more particularly to an engine. Background Technology

[0002] The engine includes a cylinder head and a throttle valve connected to the cylinder head. The cylinder head has an intake manifold for mixing air with atomized fuel. The amount of air entering the intake manifold can be controlled by adjusting the opening angle of the throttle valve, thereby changing the air-fuel ratio in the fuel mixture.

[0003] To secure the throttle body, the cylinder head typically has multiple mounting points. However, due to the irregular structure of the cylinder head, the inconsistency between these mounting points can lead to uneven stress distribution. Furthermore, the gap between the surface of some mounting points that contacts the throttle body and the main body of the cylinder head is relatively large, resulting in an unstable connection between the throttle body and the cylinder head. Additionally, some protruding mounting points not only increase the weight of the cylinder head but also increase its width. Utility Model Content

[0004] In order to overcome the shortcomings of the prior art, the purpose of this application is to provide an engine in which the connection between the cylinder head and the throttle valve is more stable, and the overall structure of the cylinder head is more compact and lighter.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] An engine includes a cylinder head, a cylinder block, and an intake system; the cylinder head has an intake manifold; the cylinder block is connected to the cylinder head and forms a combustion chamber with the cylinder head, the combustion chamber communicating with the intake manifold; the intake system includes a throttle valve connected to the cylinder head, the throttle valve communicating with the intake manifold; the cylinder head includes a cylinder head body, a first mounting portion, and a second mounting portion, the first mounting portion and the second mounting portion being connected to the cylinder head body, and the first mounting portion being located above the second mounting portion; the end of the intake manifold away from the combustion chamber is an intake port; the first mounting portion and the second mounting portion are distributed around the intake port; both the first mounting portion and the second mounting portion are tightly connected to the throttle valve and both have an end face that abuts against the throttle valve; the end face of the first mounting portion is parallel to the end face of the second mounting portion and is not on the same plane.

[0007] Furthermore, in the front-rear direction of the cylinder head, the length of the second mounting part is basically the same as the length of the first mounting part.

[0008] Furthermore, the structures of the first mounting part and the second mounting part are basically the same. Both include a cantilever and a connecting platform. The cantilever is connected to the cylinder head body, and the connecting platform is located at the end of the cantilever away from the cylinder head body and extends towards the front and upper part of the cylinder head.

[0009] Furthermore, the angle formed between the extension direction of the cantilever and the extension direction of the connecting platform is between 90° and 180°.

[0010] Furthermore, the cylinder head includes a pair of first mounting portions distributed along the left-right direction of the cylinder head, and the cylinder head has a pair of intake passages located between the pair of first mounting portions, and a second mounting portion located between the pair of intake passages.

[0011] Furthermore, the intake system also includes a connecting structure located between the throttle body and the cylinder head. The connecting structure is fitted onto the throttle body and interference-fitted onto the cylinder head.

[0012] Furthermore, the connecting structure is made of rubber.

[0013] Furthermore, a recessed fixing groove is formed on the side of the cylinder head body facing the throttle valve. The fixing groove accommodates at least part of the connecting structure. The fixing groove surrounds the intake port of the intake manifold. The connecting structure includes a main body and a plurality of protrusions arranged around the outer edge of the main body. The plurality of protrusions are distributed along the extension direction of the intake manifold. When the connecting structure is installed in the fixing groove, the protrusions can deform.

[0014] Furthermore, the connecting structure also includes an abutment portion, which is arranged on the inner edge of the main body and abuts against the throttle valve in the installation direction of the throttle valve.

[0015] Furthermore, the connecting structure also includes an abutment portion and a limiting portion connected to the abutment portion. The abutment portion is arranged on the inner edge of the main body, and the limiting portion is arranged on the inner edge of the abutment portion. The limiting portion extends from the abutment portion toward the throttle valve. When the throttle valve is connected to the connecting structure, the throttle valve abuts against the limiting portion, so that a buffer gap is formed between the abutment portion and the throttle valve.

[0016] This application provides an engine that comprises multiple mounting portions that abut against the throttle valve in a surface-to-surface contact manner and are tightly connected by fasteners. The end faces of the upper first mounting portion and the lower second mounting portion are not overlapping. This design ensures more even stress distribution on each mounting portion, improves the structural strength of each mounting portion, and makes the overall cylinder head structure more compact, contributing to the lightweight design of the engine. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the engine in an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of the cylinder head and intake / exhaust system in the embodiments of this application;

[0019] Figure 3This is a perspective view of the cylinder head in the embodiment of this application;

[0020] Figure 4 This is a cross-sectional view of the cylinder head in an embodiment of this application;

[0021] Figure 5 In the embodiments of this application Figure 3 Enlarged view of point A;

[0022] Figure 6 In the embodiments of this application Figure 3 Enlarged view of point B;

[0023] Figure 7 This is a schematic diagram of the cylinder head in an embodiment of this application;

[0024] Figure 8 This is a side view of the cylinder head in an embodiment of this application;

[0025] Figure 9 This is a cross-sectional view of the cylinder head and intake / exhaust system in an embodiment of this application;

[0026] Figure 10 In the embodiments of this application Figure 8 Enlarged view of point C;

[0027] Figure 11 This is a schematic diagram of the connection structure in the embodiment of this application. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0029] It should be noted that the terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates at least two. Unless otherwise stated, terms such as "front," "back," "left," "right," "lower," and / or "upper" are for illustrative purposes only and are not limited to a location or spatial orientation. Terms such as "comprising" or "including" indicate that the elements or objects preceding "comprising" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0030] The singular forms “a,” “the,” and “the” used in this application specification and appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0031] like Figure 1 As shown, this application provides an engine 100, which can be used as a power supply device for vehicles such as automobiles and motorcycles. In the embodiments of this application, the engine 100 is a reciprocating piston internal combustion engine, which can convert the chemical energy of fuel into the mechanical energy of piston movement and output power. The engine 100 includes a housing 10, which constitutes the main frame of the engine 100. The housing 10 includes a cylinder head cover 11, a cylinder head 12, a cylinder block 14, a crankcase 15, and an oil pan 16 connected in sequence. To clearly illustrate the technical solution of this application, the following are also provided: Figure 1 The engine 100 is located in the up-down, left-right, and front-back directions.

[0032] In this embodiment, the engine 100 is a V-type engine. The V-type engine includes a first cylinder head 12a and a second cylinder head 12b arranged one in front of the other. Both the first cylinder head 12a and the second cylinder head 12b are connected to the cylinder block 14, and their structures are basically the same except for their positions and orientations. It should be noted that "basically the same structure" means that the number and shape of their functional components are the same. The situation where some functional components are symmetrical about a specific point for ease of installation and arrangement also falls under the aforementioned shape consistency.

[0033] like Figure 1 and Figure 2 As shown, the engine 100 also includes an intake and exhaust system 20 mounted on the cylinder head 12. The intake and exhaust system 20 can deliver air into the cylinder head 12, mix the air with atomized fuel to form a fuel mixture, and also discharge the exhaust gas formed after the combustion of the fuel mixture from the cylinder head 12.

[0034] The intake and exhaust system 20 includes an intake system 21, which includes an air filter (not shown), an intake manifold 211, and a throttle valve 212. The air filter is used to absorb and filter air. The intake manifold 211 connects the air filter and the cylinder head 12, and it can receive and deliver air filtered by the air filter.

[0035] like Figure 2 and Figure 3As shown, in one implementation, the cylinder head 12 and the cylinder block 14 form a combustion chamber 141 for the reciprocating motion of the piston mechanism. The cylinder head 12 includes a ventilation passage 121 and a valve guide 122. The ventilation passage 121 communicates with the combustion chamber 141, and the valve guide 122 forms a channel 1221 communicating with the ventilation passage 121. The intake and exhaust system 20 also includes a valve 22 passing through the valve guide 122. At least a portion of the valve 22 extends into the ventilation passage 121 and controls the connection or disconnection between the ventilation passage 121 and the combustion chamber 141.

[0036] Specifically, the intake and exhaust system 20 also includes a valve sealing ring 23, which is installed on the cylinder head 12 and located at the connection between the air passage 121 and the combustion chamber 141. The valve sealing ring 23 is adapted to accommodate at least part of the valve 22. The inner edge of the valve 22 is sealed to form a cylindrical gill 231, and the axis of the gill 231 forms an angle greater than 0° with the axis of the valve 22.

[0037] By setting the above, the axis of the channel 1221 where the valve 22 is installed forms an angle greater than 0° with the axis of the nozzle 231, thereby reducing the large pressure loss when the airflow passes through the nozzle 231 and improving the working efficiency of the engine 100.

[0038] like Figure 4 As shown, in one implementation, the ventilation duct 121 includes an intake duct 1211 and an exhaust duct 1212 capable of delivering a fuel-air mixture into the combustion chamber 141. The number of intake ducts 1211 and the number of exhaust ducts 1212 are the same, and both have at least one.

[0039] Each intake manifold 211 corresponds to an intake port 1211, and the air output from the air filter is evenly distributed to different intake ports 1211 through the intake manifold 211. A throttle valve 212 is mounted on the cylinder head 12, connecting the intake manifold 211 and the intake ports 1211. By adjusting the opening angle of the throttle valve 212, the amount of air entering the intake ports 1211 is increased or decreased. The intake ports 1211 have opposing intake ports 1211a and outlet ports 1211b. Intake port 1211a is connected to the throttle valve 212 and is used to receive the air supplied by the throttle valve 212. Outlet port 1211b is connected to the combustion chamber 141 and is used to deliver the fuel-air mixture from the intake ports 1211 to the combustion chamber 141. The exhaust duct 1212 has an intake end 1212a and an exhaust end 1212b, with the intake end 1212a communicating with the combustion chamber 141. When the engine 100 is a turbocharged engine, the exhaust end 1212b communicates with a turbine (not shown) mounted on the cylinder head 12. When the engine 100 is a naturally aspirated engine, the exhaust end 1212b communicates with an exhaust manifold (not shown) to discharge exhaust gases from the engine 100 through the exhaust manifold.

[0040] Valve guide 122 includes an intake valve guide 1222 communicating with the intake passage 1211 and an exhaust valve guide 1223 communicating with the exhaust passage 1212. Valve 22 includes an intake valve 221 and an exhaust valve 222. The intake valve 221 passes through a first channel 1221a formed by the intake valve guide 1222, and the intake valve 221 can control the connection or disconnection between the intake passage 1211 and the combustion chamber 141. The exhaust valve 222 passes through a second channel 1221b formed by the exhaust valve guide 1223, and the exhaust valve 222 can control the connection or disconnection between the exhaust passage 1212 and the combustion chamber 141.

[0041] like Figure 5 and Figure 6 As shown, the valve sealing ring 23 includes an intake valve sealing ring 232 and an exhaust valve sealing ring 233. The intake valve sealing ring 232 is located at the connection between the intake duct 1211 and the combustion chamber 141, and houses at least a portion of the intake valve 221. The inner edge of the intake valve sealing ring 232 surrounds a cylindrical intake manifold 2311. The intake manifold 2311 serves as a transition structure connecting the intake duct 1211 and the combustion chamber 141. Air entering the intake duct 1211 changes its flow direction through the intake manifold 2311, causing a deflection in the airflow direction to reduce pressure loss generated during airflow within the intake duct 1211. The exhaust valve sealing ring 233 is located at the connection between the exhaust duct 1212 and the combustion chamber 141, and houses at least a portion of the exhaust valve 222. The inner edge of the exhaust valve sealing ring 233 surrounds a cylindrical exhaust manifold 2312. The exhaust port 2312 serves as a transitional structure connecting the exhaust duct 1212 and the combustion chamber 141. The air entering the exhaust duct 1212 changes its flow direction through the exhaust port 2312, causing the airflow direction to shift, thereby reducing the pressure loss generated when the exhaust gas flows through the exhaust port 2312 and improving exhaust efficiency.

[0042] like Figures 4 to 6 As shown, in one implementation, the axis of the intake vent 2311 forms a first angle α with the axis of the first channel 1221a, and the axis of the exhaust vent 2312 forms a second angle β with the axis of the second channel 1221b, the second angle β being smaller than the first angle α.

[0043] As one implementation, the first included angle α ranges from 5° to 15°, and the second included angle β ranges from 0° to 10°. Further, the first included angle α ranges from 7° to 12°, and the second included angle β ranges from 3° to 8°. More preferably, the first included angle α is 10°, and the second included angle β is 6°.

[0044] It should be noted that if the first included angle α is too small, it will result in a large angle between the intake manifold 2311 and the intake duct 1211, leading to a significant pressure loss at the junction of the intake duct 1211 and the intake manifold 2311. If the first included angle α is too large, this design of the intake duct 1211 and intake manifold 2311 will excessively encroach on the space of the exhaust duct 1212 in the cylinder head 12, affecting the exhaust efficiency of the engine 100. If the range of the second included angle β is too small, the pressure loss generated when the exhaust gas passes through the exhaust manifold 2312 will be significant, affecting the exhaust efficiency of the exhaust gas passing through the exhaust duct 1212. If the range of the second included angle β is too large, with the length of the intake duct 1211 remaining unchanged, a longer exhaust duct 1212 is required to meet the exhaust requirements of the engine 100, resulting in an increase in the size and weight of the engine 100.

[0045] The above configuration makes the junction between the intake duct 1211 and the intake nozzle 2311 smoother, reducing the pressure loss generated when the airflow passes through the junction of the intake duct 1211 and the intake nozzle 2311. Furthermore, while ensuring the compactness of the engine 100, it reduces the pressure loss of the exhaust gas flow, thus ensuring the exhaust performance of the engine 100.

[0046] In one implementation, the cylinder head 12 includes a splice portion 123 surrounding the intake manifold 1211 and connected to the intake valve sealing ring 232. The splice portion 123 is adapted to accommodate the intake valve sealing ring 232, and the intake valve sealing ring 232 is interference-fitted with the splice portion 123. The splice portion 123 and the intake valve sealing ring 232 surround to form an intake manifold 2311, thereby extending the axial length of the intake manifold 2311 and reducing the pressure loss of airflow passing through the intake manifold 2311.

[0047] Specifically, the splicing part 123 forms a first limiting groove 1231, the inner diameter of which is larger than the inner diameter of the air intake duct 1211. The inner edge of the air intake valve sealing ring 232 is connected to the inner wall of the air intake duct 1211, and a smooth curved surface is formed at the junction of the two.

[0048] In this embodiment, the cylinder head 12 forms a second limiting groove 124 at the exhaust end 1212b of the exhaust passage 1212, and the exhaust valve sealing ring 233 is disposed in the second limiting groove 124 and is interference-fitted with the cylinder head 12.

[0049] As one implementation, the outer peripheral wall of the intake vent 2311 includes a first part 2311a and a second part 2311b. The surface areas of the first part 2311a and the second part 2311b are basically the same. The first part 2311a is closer to the intake port 1211a than the second part 2311b. Both the first part 2311a and the second part 2311b are formed by grinding. The grinding depth of the first part 2311a is greater than the grinding depth of the second part 2311b. Through the above arrangement, the junction between the intake duct 1211 and the intake vent 2311 is made smoother, reducing the pressure loss generated when the airflow passes through the junction of the intake duct 1211 and the intake vent 2311. In addition, while minimizing interference with the exhaust duct 1212, the flow cross-sectional area of ​​the intake duct 1211 is further increased, thereby increasing the intake volume of the intake duct 1211.

[0050] like Figure 7 As shown, in one implementation, the cylinder head 12 includes multiple mounting portions 129, each of which is tightly connected to the throttle valve 212 via fasteners, and each mounting portion 129 has an end face that abuts against the throttle valve 212. The multiple mounting portions 129 include a first mounting portion 129a and a second mounting portion 129b. The cylinder head 12 includes a cylinder head body 126, and the first mounting portion 129a and the second mounting portion 129b are connected to the cylinder head body 126, with the first mounting portion 129a located above the second mounting portion 129b. The intake manifold 121 has an intake port for receiving air, and the first mounting portion 129a and the second mounting portion 129b are arranged around the intake port. Both the first mounting portion 129a and the second mounting portion 129b have an end face that abuts against the throttle valve 212. The end face of the first mounting portion 129a is parallel to the end face of the second mounting portion 129b, but they are not on the same plane.

[0051] To clearly illustrate the technical solution of this application, the following are also provided: Figure 7 The cylinder head 12 shown is positioned vertically, horizontally, and front-back.

[0052] Specifically, in the front-rear direction of the cylinder head 12, the length of the second mounting portion 129b is substantially the same as the length of the first mounting portion 129a. It should be noted that, due to tolerances inherent in the manufacturing process of the cylinder head 12, these tolerances may be caused by deformation during molding, material handling, or assembly. Therefore, the statement in this application that the lengths are substantially the same means that, after considering the tolerances present in actual conditions, the actual deviation between the length of the second mounting portion 129b and the length of the first mounting portion 129a does not exceed a 5% tolerance.

[0053] In this embodiment of the application, the cylinder head 12 includes a pair of first mounting portions 129a, which are distributed along the left and right directions of the cylinder head 12. The cylinder head 12 has a pair of intake passages 1211, which are located between the pair of first mounting portions 129a, and a second mounting portion 129b is located between the pair of intake passages 1211.

[0054] The above-mentioned configuration makes the stress on each mounting part 129 more uniform, resulting in higher overall structural strength and better modal properties of the cylinder head 12, and makes the overall structure of the cylinder head 12 more compact, which helps to achieve lightweight design of the engine 100.

[0055] like Figure 8 As shown, in one implementation, the structures of the first mounting part 129a and the second mounting part 129b are basically the same. Both include a cantilever 1293 and a connecting platform 1294. One end of the cantilever 1293 is connected to the cylinder head body 126, and the other end is connected to the connecting platform 1294. The connecting platform 1294 extends towards the front and upper part of the cylinder head 12.

[0056] Specifically, the extension direction of the cantilever 1293 forms an angle γ with the extension direction of the connecting platform 1294, and the angle γ ranges from 90° to 180°.

[0057] The above settings facilitate the installation of the throttle body 212 and reduce intake resistance.

[0058] like Figures 9 to 11 As shown, in one implementation, the intake system 21 also includes a connecting structure 215 connecting the throttle valve 212 and the cylinder head 12. The connecting structure 215 is annular and arranged around the intake port of the intake passage 1211. The throttle valve 212 is connected to the cylinder head 12 through the connecting structure 215. The throttle valve 212 has an end 2121 connected to the cylinder head 12. The connecting structure 215 is fitted onto the end 2121 of the throttle valve 212. The cylinder head body 126 has an inwardly recessed fixing groove 125 on the side facing the throttle valve 212. The fixing groove 125 accommodates at least a portion of the connecting structure 215. The fixing groove 125 surrounds the intake port of the intake passage 1211, and the connecting structure 215 is interference-fitted into the fixing groove 125.

[0059] The above settings reduce the difficulty of installing the throttle body 212, and eliminate the need for bolts, pins, or other fasteners when installing the throttle body 212, making the connection between the throttle body 212 and the cylinder head 12 more compact and reducing the overall weight of the engine 100.

[0060] Furthermore, the inner edge of the connecting structure 215 forms a continuous curved surface with the inner wall of the intake duct 1211 to avoid pressure loss when air enters the intake duct 1211.

[0061] Specifically, the connecting structure 215 is made of rubber and has a metal part 2155 inside, thereby improving the structural strength of the connecting structure 215 and extending its service life.

[0062] In one implementation, the connecting structure 215 includes a main body 2151 and a protrusion 2152. The main body 2151 forms the main frame of the connecting structure 215, and the protrusion 2152 is disposed on the outer edge of the main body 2151. When the connecting structure 215 is installed in the fixing groove 125, the protrusion 2152 surrounding the outer edge of the main body 2151 deforms to increase the stability and sealing of the connecting structure 215 installed in the fixing groove 125.

[0063] Furthermore, the connecting structure 215 also includes an abutment portion 2153, which is disposed on the inner edge of the main body portion 2151. The abutment portion 2153 abuts against the throttle valve 212 in the mounting direction of the throttle valve 212 to avoid direct contact between the throttle valve 212 and the cylinder head 12. Since the engine 100 will vibrate when it is working, the above arrangement can reduce the hard friction between the throttle valve 212 and the cylinder head 12.

[0064] In this structure, part of the metal part 2155 is located inside the abutment part 2153, and another part of the metal part 2155 is located inside the main body part 2151, thereby improving the structural strength of the connecting structure 215 and extending its service life.

[0065] Optionally, the connecting structure 215 includes an abutment portion 2153 and a limiting portion 2154 connected to the abutment portion 2153. The abutment portion 2153 is arranged on the inner edge of the main body portion 2151, and the limiting portion 2154 is disposed on the inner edge of the abutment portion 2153. The limiting portion 2154 extends from the abutment portion 2153 toward the throttle valve 212. When the throttle valve 212 is connected to the connecting structure 215, the throttle valve 212 abuts against the limiting portion 2154, thereby forming a buffer gap between the abutment portion 2153 and the throttle valve 212. This avoids direct contact between the throttle valve 212 and the abutment portion 2153, reducing wear on the end 2121 of the throttle valve 212.

[0066] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An engine, comprising: Cylinder head, which has an intake manifold; A cylinder block, which is connected to the cylinder head and forms a combustion chamber with the cylinder head, the combustion chamber being in communication with the intake manifold; An intake system, including a throttle valve connected to the cylinder head and communicating with the intake manifold; The cylinder head is characterized in that it includes a cylinder head body, a first mounting portion and a second mounting portion, the first mounting portion and the second mounting portion are connected to the cylinder head body, and the first mounting portion is located above the second mounting portion. The end of the intake manifold away from the combustion chamber is the intake port. The first mounting portion and the second mounting portion are distributed around the intake port. The first mounting portion and the second mounting portion are both tightly connected to the throttle valve and both have an end face that abuts against the throttle valve. The end face of the first mounting portion is parallel to the end face of the second mounting portion and is not on the same plane.

2. The engine according to claim 1, characterized in that, In the front-rear direction of the cylinder head, the length of the second mounting portion is substantially the same as the length of the first mounting portion.

3. The engine according to claim 1, characterized in that, The first mounting part and the second mounting part have basically the same structure. Both include a cantilever and a connecting platform. The cantilever is connected to the cylinder head body, and the connecting platform is located at the end of the cantilever away from the cylinder head body and extends towards the front and upper part of the cylinder head.

4. The engine according to claim 3, characterized in that, The angle between the extension direction of the cantilever and the extension direction of the connecting platform is between 90° and 180°.

5. The engine according to claim 1, characterized in that, The cylinder head includes a pair of first mounting portions distributed along the left-right direction of the cylinder head. The cylinder head has a pair of intake passages located between the pair of first mounting portions, and a second mounting portion located between the pair of intake passages.

6. The engine according to claim 1, characterized in that, The intake system also includes a connecting structure located between the throttle body and the cylinder head. The connecting structure is fitted onto the throttle body and interference-fitted onto the cylinder head.

7. The engine according to claim 6, characterized in that, The connecting structure is made of rubber.

8. The engine according to claim 6, characterized in that, The cylinder head body has an inwardly recessed fixing groove on the side facing the throttle valve. The fixing groove accommodates at least part of the connecting structure. The fixing groove surrounds the intake port of the intake manifold. The connecting structure includes a main body and a protrusion arranged around the outer edge of the main body. When the connecting structure is installed in the fixing groove, the protrusion can deform.

9. The engine according to claim 8, characterized in that, The connecting structure further includes an abutment portion, which is arranged on the inner edge of the main body and abuts against the throttle valve in the installation direction of the throttle valve.

10. The engine according to claim 8, characterized in that, The connecting structure further includes an abutment portion and a limiting portion connected to the abutment portion. The abutment portion is arranged on the inner edge of the main body portion, and the limiting portion is disposed on the inner edge of the abutment portion. The limiting portion extends from the abutment portion toward the throttle valve. When the throttle valve is connected to the connecting structure, the throttle valve abuts against the limiting portion, thereby forming a buffer gap between the abutment portion and the throttle valve.

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