Engine and vehicle

Abstract

The present application discloses are an engine and a vehicle. The engine comprises: a cylinder block, a first cylinder head and a second cylinder head; a first inner flow guide wall is formed in a first oil return cavity; the first inner flow guide wall is inclined from top to bottom toward a first oil return hole; a second inner flow guide wall is formed in the second oil return cavity; the second inner flow guide wall is inclined from top to bottom toward a second oil return hole; and the inclination angle of the second inner flow guide wall relative to the horizontal direction is greater than the inclination angle of the first inner flow guide wall relative to the horizontal direction.

Description

Engines and vehicles

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application No. 202411504083.8, filed on October 25, 2024, entitled "Engine and Vehicle", the entire contents of which are incorporated herein by reference.

[0003] Technical Field

[0004] This application relates to the field of vehicle manufacturing technology, and more particularly to an engine and a vehicle having the engine. Background Technology

[0005] Currently, vehicles are generally equipped with inline or V-type engines, while horizontally opposed engines are less common. However, horizontally opposed engines have their own unique advantages. First, they have a low center of gravity, which increases stability at high speeds, improves cornering performance, and increases grip, thereby enhancing driving safety. Second, their cylinder layout is a symmetrical and stable structure. When the piston moves, the first-order inertial forces and torques generated by the cylinders on both sides cancel each other out, resulting in more stable and smooth engine operation and improved ride comfort.

[0006] In some existing vehicles, a significant amount of engine oil accumulates at the bottom of the timing chamber during use, reducing the amount of oil circulating in the lubrication system. This results in the engine requiring more oil to be added, while the timing chain remains submerged below the oil level in the dead zone. The timing chain agitates the oil, generating a large amount of oil vapor, which increases the burden on the crankcase ventilation system. Adding an oil pump mounting structure to the cylinder block not only complicates the structure but also encroaches on the space for other components, resulting in significant disadvantages in overall weight and cost, indicating room for improvement. Summary of the Invention

[0007] This application aims to solve at least one of the technical problems existing in the prior art. To this end, this application proposes an engine with high oil return efficiency on both sides, which can avoid the formation of oil dead zones in the first and second cylinder heads, and will not affect the circulating oil volume of the lubrication system, saving the amount of engine oil added, and can prevent the timing chain from stirring the oil, reducing the amount of oil and reducing the burden on the crankcase ventilation system.

[0008] An engine according to an embodiment of this application includes: a cylinder block, a timing chamber formed therein, and an oil pan located below the timing chamber; a first cylinder head and a second cylinder head, the first cylinder head and the second cylinder head being mounted opposite each other on both sides of the cylinder block; the first cylinder head and the cylinder block defining a first oil return chamber communicating with the timing chamber, and the second cylinder head and the cylinder block defining a second oil return chamber communicating with the timing chamber; the bottom of the first oil return chamber having a first oil return hole communicating with the oil pan, and the bottom of the second oil return chamber having a connection to the oil pan. The timing chain in the cylinder body is adapted to drive at least a portion of the engine oil to flow toward the second oil return chamber. A first inner guide wall is formed in the first oil return chamber near the cylinder body, and the first inner guide wall is inclined downwards toward the first oil return hole. A second inner guide wall is formed in the second oil return chamber near the cylinder body, and the second inner guide wall is inclined downwards toward the second oil return hole. The angle of inclination of the second inner guide wall relative to the horizontal direction is greater than the angle of inclination of the first inner guide wall relative to the horizontal direction.

[0009] According to the engine embodiment of this application, by setting a sunken first oil return chamber and a sunken second oil return chamber on both sides of the engine, the oil return efficiency on both sides of the engine can be improved respectively. This can avoid the formation of oil dead zones in the first and second cylinder heads, and will not affect the circulating oil volume of the lubrication system, saving the amount of engine oil added. It can also prevent the timing chain from stirring the oil, reduce the amount of oil and gas, and reduce the burden on the crankcase ventilation system. Furthermore, by setting the inclination angle of the second inner guide wall to be greater than that of the first inner guide wall, the oil return efficiency on the left and right sides of the engine can be balanced, so that the whole machine has good lubrication performance.

[0010] According to some embodiments of the engine in this application, the bottom of the first oil return chamber is formed with a first oil return chamber bottom surface, the first oil return hole is disposed on the first oil return chamber bottom surface, and the inner wall of the first oil return chamber also includes a first outer drainage wall connected to the first oil return chamber bottom surface and distributed opposite to the first inner drainage wall. The first outer drainage wall is inclined from top to bottom toward the first oil return hole.

[0011] And / or, the bottom of the second oil return chamber is formed with a second oil return chamber bottom surface, the second oil return hole is provided on the second oil return chamber bottom surface, and the inner wall of the second oil return chamber also includes a second outer drainage wall connected to the second oil return chamber bottom surface and distributed opposite to the second inner drainage wall, the second outer drainage wall being inclined from top to bottom toward the second oil return hole.

[0012] According to some embodiments of the engine in this application, the bottom surface of the first oil return chamber is provided with an upwardly protruding first oil return chamber oil weir, and the oil in the first oil return chamber is adapted to be diverted from the first oil return chamber oil weir to flow to the first oil return hole respectively.

[0013] According to some embodiments of the engine in this application, the bottom of the first oil return chamber is further formed with a first oil drain groove and a second oil drain groove located on both sides of the oil weir of the first oil return chamber. The oil in the first oil return chamber is adapted to flow to the first oil return hole through the first oil drain groove, the oil weir of the first oil return chamber and the second oil drain groove respectively.

[0014] According to some embodiments of the engine in this application, the first oil return chamber weir includes a front side surface, an arc surface, and a rear side surface. The front side surface is formed on the side of the first oil return chamber weir facing the first oil drain groove and is in contact with the inner wall of the first oil drain groove. The rear side surface is formed on the side of the first oil return chamber weir facing the second oil drain groove and is in contact with the inner wall of the second oil drain groove. The arc surface is formed on the side of the first oil return chamber weir facing the first oil return hole.

[0015] According to some embodiments of the engine in this application, the first outer drain wall includes a first drain front arc surface and a first drain rear arc surface connected together. The first drain front arc surface extends to connect with the first oil drain groove and is adapted to guide flow toward the first oil drain groove. The first drain rear arc surface extends to connect with the second oil drain groove and is adapted to guide flow toward the second oil drain groove.

[0016] According to some embodiments of the engine in this application, the inner wall of the first oil return chamber is further provided with a first inner side edge surface connected to the upper part of the first inner drain wall. The first inner side edge surface is set to be inclined from top to bottom close to the bottom surface of the first oil return chamber, and the inclination angle of the first inner side edge surface relative to the bottom surface of the first oil return chamber is A1, and satisfies: 10°≤A1≤30°.

[0017] And / or, the inner wall of the first oil return cavity is further provided with a first outer edge surface connected to the top of the first outer drainage wall. The first outer edge surface is higher than the bottom surface of the first oil return cavity, and the height difference between the first outer edge surface and the bottom surface of the first oil return cavity is L1, which satisfies: 15mm≤L1≤30mm.

[0018] According to some embodiments of the engine in this application, the first outer drainage wall is constructed as an inclined curved surface, and the slope of the inclined curved surface gradually increases from top to bottom and then gradually decreases.

[0019] The tilt angle of the inclined surface relative to the horizontal direction is A2, and satisfies: 30°≤A2≤60°.

[0020] And / or, the inclination angle of the first external drainage wall relative to the horizontal direction is A2, and the inclination angle of the second external drainage wall relative to the horizontal direction is A3, and satisfies: (A3-A2) / A2≥0.1;

[0021] And / or, the inclination angle of the first inner drainage wall relative to the horizontal direction is A4, and the inclination angle of the second inner drainage wall relative to the horizontal direction is A5, and satisfies: (A5-A4) / A4≥0.1.

[0022] According to some embodiments of the engine in this application, the first inner drainage wall has an inclination angle of A4 relative to the horizontal direction, and satisfies: 25°≤A4≤70°.

[0023] According to some embodiments of the engine in this application, the bottom of the first cylinder head is connected to a first oil return pipe, and the first oil return hole is connected to the oil pan through the first oil return pipe.

[0024] And / or, the bottom of the second cylinder head is connected to a second oil return pipe, and the second oil return hole is connected to the oil pan through the second oil return pipe.

[0025] According to some embodiments of the engine in this application, the outlet end of the second oil return pipe is higher than the outlet end of the first oil return pipe, and the height difference between the outlet end of the second oil return pipe and the outlet end of the first oil return pipe is L2, which satisfies: 30mm≤L2≤45mm.

[0026] According to some embodiments of the engine in this application, the extension direction of the first oil return pipe is inclined at an angle B1 relative to the horizontal plane, and satisfies: B1≥30°; the extension direction of the second oil return pipe is inclined at an angle B2 relative to the horizontal plane, and satisfies: B2≥30°.

[0027] According to some embodiments of the engine in this application, the upper end of the first oil return pipe is detachably installed at the first oil return hole via a first connector, and a first sealing element is provided between the first oil return pipe and the inner wall of the first oil return hole.

[0028] According to some embodiments of the engine in this application, the upper end of the second oil return pipe is detachably installed at the second oil return hole via a second connector, and a second seal is provided between the second oil return pipe and the inner wall of the second oil return hole.

[0029] This application also proposes a vehicle.

[0030] The vehicle according to the embodiments of this application is equipped with an engine according to any of the above embodiments.

[0031] The vehicle and the engine described above have the same advantages over the prior art, which will not be repeated here.

[0032] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0033] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0034] Figure 1 is a front view of an engine according to an embodiment of this application;

[0035] Figure 2 is a partial structural schematic diagram of an engine according to an embodiment of this application;

[0036] Figure 3 is a partial structural schematic diagram of an engine according to an embodiment of this application;

[0037] Figure 4 is a schematic diagram of the structure of the first oil return pipe of the engine according to an embodiment of this application;

[0038] Figure 5 is a schematic diagram of the structure of the second oil return pipe of the engine according to an embodiment of this application;

[0039] Figure 6 is a partial cross-sectional view of the first oil return chamber of an engine according to an embodiment of this application.

[0040] Figure label:

[0041] Engine 100,

[0042] Cylinder block 1, timing chamber 11, oil pan 12, right oil return port 121, left oil return port 122, first cylinder head 2, first oil return chamber 21, first inner drain wall 22, bottom surface of first oil return chamber 23, oil weir of first oil return chamber 231, front side surface of oil weir of first oil return chamber 232, arc surface of oil weir of first oil return chamber 233, rear side surface of oil weir of first oil return chamber 234, first outer drain wall 24, front arc surface of first drain 241, rear arc surface of first drain 242, first inner edge surface 25, first outer edge surface 26, first oil return hole 27, first drain groove 28, second drain groove 29, second cylinder head 3. Second oil return chamber 31, second inner drainage wall 32, bottom surface of second oil return chamber 33, second outer drainage wall 34, second oil return hole 35, first oil return pipe 4, first connecting joint 41, first connecting hole 411, first connecting piece 412, first mounting groove 42, first seal 43, second connecting joint 44, right side sealing gasket 45, corrugated section 46, second oil return pipe 5, third connecting joint 51, third connecting hole 511, second connecting piece 512, second mounting groove 52, second seal 53, fourth connecting joint 54, left side sealing gasket 55, timing chain 6, timing sprocket 7. Embodiments of the present invention

[0043] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0044] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, features defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0046] Unless otherwise specified, the front-back direction in this application refers to the longitudinal direction of the vehicle, i.e., the X direction; the left-right direction refers to the lateral direction of the vehicle, i.e., the Y direction; and the up-down direction refers to the vertical direction of the vehicle, i.e., the Z direction.

[0047] The engine 100 according to an embodiment of this application is described below with reference to Figures 1-6. By providing a sunken first oil return chamber 21 and a sunken second oil return chamber 31 on both sides of the engine 100, and the angle of inclination of the second inner guide wall 32 relative to the horizontal direction is greater than the angle of inclination of the first inner guide wall 22 relative to the horizontal direction, the oil return efficiency on both sides of the engine 100 can be improved respectively. This can avoid the formation of oil dead zones in the first cylinder head 2 and the second cylinder head 3, and will not affect the circulating oil volume of the lubrication system, saving the amount of engine oil added. It can also prevent the timing chain 6 from stirring the oil, reduce the amount of oil and gas, and reduce the burden on the crankcase ventilation system.

[0048] As shown in Figures 1-6, an engine 100 according to one embodiment of this application includes: a cylinder block 1, a first cylinder head 2, and a second cylinder head 3.

[0049] A timing chamber 11 is formed inside the cylinder block 1. The cylinder block 1 is provided with an oil pan 12 located below the timing chamber 11. The cylinder block 1 is the main body of the engine 100. The cylinder block 1 contains a combustion chamber and a piston movement chamber, etc., and a timing chamber 11 is formed on one side of the cylinder block 1. The timing chamber 11 is used to accommodate the timing chain 6, timing sprocket 7, and other structures. An oil pan 12 is provided on the lower side of the cylinder block 1. The oil pan 12 and the timing chamber 11 are spaced apart in the vertical direction. The oil pan 12 is a storage container for the engine oil of the engine 100. It is used to collect and store the engine oil of the engine 100. When the engine 100 is working, the oil can be delivered to various parts of the engine 100 by an oil pump to provide lubrication, cooling and cleaning to ensure the safe operation of each part.

[0050] The first cylinder head 2 and the second cylinder head 3 are installed opposite each other on both sides of the cylinder body 1. The first cylinder head 2 and the cylinder body 1 define a first oil return chamber 21 that communicates with the timing chamber 11. The second cylinder head 3 and the cylinder body 1 define a second oil return chamber 31 that communicates with the timing chamber 11. The bottom of the first oil return chamber 21 is provided with a first oil return hole 27 that communicates with the oil pan 12. The bottom of the second oil return chamber 31 is provided with a second oil return hole 35 that communicates with the oil pan 12. The timing chain 6 in the cylinder body 1 is adapted to drive at least a portion of the engine oil to flow toward the second oil return chamber 31.

[0051] In this embodiment, the engine 100 is specifically a horizontally opposed engine 100. The first cylinder head 2 and the second cylinder head 3 are horizontally opposed and connected to the two sides of the cylinder block 1. For example, the first cylinder head 2 and the second cylinder head 3 are distributed in the left and right directions on the two sides of the cylinder block 1, and the timing chamber 11 is located on the front side of the engine 100. The first cylinder head 2 and the second cylinder head 3 respectively seal the two ends of the cylinder block 1, and the first cylinder head 2 and the second cylinder head 3 usually contain components such as valves, spark plugs or fuel injectors.

[0052] In this configuration, the upper sides of the first cylinder head 2 and the second cylinder head 3 are the intake sides, and the lower sides are the exhaust sides. The lower region of the first cylinder head 2 and the cylinder block 1 define a first oil return chamber 21. The upper end of the first oil return chamber 21 is connected to the timing chamber 11, and the bottom of the first oil return chamber 21 is provided with a first oil return hole 27, which is connected to the oil pan 12. This allows the engine oil in the timing chamber 11 to flow to the oil pan 12 through the first oil return hole 27 of the first oil return chamber 21, thus achieving oil collection. The lower area of ​​the second cylinder head 3 and the cylinder block 1 define the second oil return chamber 31. The upper end of the second oil return chamber 31 is connected to the timing chamber 11, and the bottom of the second oil return chamber 31 is provided with a second oil return hole 35, which is connected to the oil pan 12. In this way, the engine oil in the timing chamber 11 can flow to the oil pan 12 through the second oil return hole 35 of the second oil return chamber 31 to achieve oil collection. Thus, by setting the sinking first oil return chamber 21 and sinking second oil return chamber 31, the oil return efficiency of the engine oil on the left and right sides of the timing chamber 11 is improved.

[0053] Looking from back to front, the timing chain 6 rotates clockwise. The first cylinder head 2 is located on the right side of the cylinder block 1, and the second cylinder head 3 is located on the left side of the cylinder block 1. When the timing chain 6 on the left side of the cylinder block 1 rotates clockwise, it will drive at least a portion of the engine oil to flow toward the second oil return chamber 31, so that the engine oil in the timing chain 6 can be returned through the second oil return chamber 31. And when the timing chain 6 on the right side of the cylinder block 1 rotates clockwise, it will drive at least a portion of the engine oil to flow toward the first oil return chamber 21, so that the engine oil in the timing chain 6 can be returned through the first oil return chamber 21.

[0054] In the first oil return chamber 21, a first inner guide wall 22 is formed on the side near the cylinder body 1. The first inner guide wall 22 is inclined from top to bottom toward the first oil return hole 27. In the second oil return chamber 31, a second inner guide wall 32 is formed on the side near the cylinder body 1. The second inner guide wall 32 is inclined from top to bottom toward the second oil return hole 35.

[0055] Both the first inner drain wall 22 and the second inner drain wall 32 have the function of guiding the oil to flow along a specific path. The first oil return chamber 21 has a first inner drain wall 22 formed on the inner wall near the cylinder 1. The first inner drain wall 22 is constructed with an inclined structure and is inclined from top to bottom towards the first oil return hole 27. In this way, the oil in the cylinder 1 and the timing chamber 11 can flow from the inside to the outside along the first inner drain wall 22 to the first oil return chamber 21 and the first oil return hole 27. The second oil return chamber 31 has a second inner drain wall 32 formed on the inner wall near the cylinder 1. The second inner drain wall 32 is constructed with an inclined structure and is inclined from top to bottom towards the second oil return hole 35. In this way, the oil in the cylinder 1 and the timing chamber 11 can flow from the inside to the outside along the second inner drain wall 32 to the second oil return chamber 31 and the second oil return hole 35, so as to realize the drainage of oil on both sides of the cylinder 1.

[0056] Furthermore, the angle of inclination of the second inner drainage wall 32 relative to the horizontal direction is greater than the angle of inclination of the first inner drainage wall 22 relative to the horizontal direction. In other words, the guiding effect of the second inner drainage wall 32 is greater than the guiding effect of the first inner drainage wall 22, which means that the oil return efficiency of the second oil return chamber 31 is greater than the oil return efficiency of the first oil return chamber 21.

[0057] The timing chain 6 is connected to the end of the camshaft. When the camshaft drives the timing chains 6 on both sides to rotate clockwise, the timing chain 6 on the left side carries engine oil to the left side of the engine 100. The oil return from the left side of the engine 100 is more difficult than from the right side. By setting the inclination angle of the second inner guide wall 32 to be greater than that of the first inner guide wall 22, and by having the second inner guide wall 32 guide the engine oil to the second oil return chamber 31, the oil return efficiency on the left side of the engine 100 can be improved. Meanwhile, the timing chain 6 on the right side throws the engine oil to the left, reducing the amount of oil remaining on the right side of the engine 100. The timing chain 6 also throws the oil to the left into the second oil return chamber 31, achieving oil return from the right side. This balances the oil return efficiency on both sides of the engine 100 caused by the rotation direction of the timing chain 6. The setup is simple and provides good oil return.

[0058] Therefore, for the horizontally opposed engine 100, a double timing sprocket 7 is provided, which makes the exhaust side of the first cylinder head 2 and the second cylinder head 3 lower. This part of the cavity, which is lower than the oil return passage inlet of the cylinder block 1, becomes an oil accumulation dead zone, which will affect the oil return efficiency. In this embodiment, by setting a sunken first oil return chamber 21 and a sunken second oil return chamber 31 on both sides of the engine 100, the oil return efficiency on both sides of the engine 100 can be improved respectively. This can avoid the formation of oil accumulation dead zones in the first cylinder head 2 and the second cylinder head 3, and will not affect the circulating oil volume of the lubrication system, saving the amount of engine oil added. In addition, the timing chain 6 will not be immersed in the oil accumulation dead zone, which will cause the timing chain 6 to stir the oil. This reduces the amount of oil and gas, reduces the burden on the crankcase ventilation system, and has high oil return efficiency, effectively avoiding the risk of low oil pressure and ensuring that the whole machine has good lubrication performance.

[0059] In some embodiments, a first oil return cavity bottom surface 23 is formed at the bottom of the first oil return cavity 21, and a first oil return hole 27 is disposed on the first oil return cavity bottom surface 23. The inner wall of the first oil return cavity 21 also includes a first outer drainage wall 24 connected to the first oil return cavity bottom surface 23 and distributed opposite to the first inner drainage wall 22. The first outer drainage wall 24 is inclined from top to bottom to the first oil return hole 27.

[0060] As shown in Figure 2, the bottom surface 23 of the first oil return chamber is located at the bottom of the first oil return chamber 21. The oil can flow back into the first oil return chamber 21 and be accommodated on the bottom surface 23. The bottom surface 23 of the first oil return chamber is flat and has a first oil return hole 27 for guiding the oil from the bottom surface 23 of the first oil return chamber into the oil pan 12. The inner wall of the first oil return chamber 21 also includes a first outer drainage wall 24. The first outer drainage wall 24 and the first inner drainage wall 22 are distributed on the outer periphery of the bottom surface 23 of the first oil return chamber and are connected to the bottom surface 23 of the first oil return chamber. The first outer drainage wall 24 is inclined and slopes from top to bottom toward the first oil return hole 27 to guide the oil from the outside of the first oil return chamber 21.

[0061] The engine oil in the cylinder block 1 and timing chamber 11 can flow from the outside to the inside along the first outer drain wall 24 to the first oil return chamber 21 and the first oil return hole 27. Combined with the guiding effect of the first inner drain wall 22, the engine oil on the outer periphery of the first oil return chamber 21 is guided in a direction inclined towards the center of the first oil return chamber 21, which can effectively improve the oil return efficiency. It has a simple structure and good guiding effect.

[0062] In other embodiments, the bottom of the second oil return chamber 31 is formed with a second oil return chamber bottom surface 33, and the second oil return hole 35 is disposed at the second oil return chamber bottom surface 33. The inner wall of the second oil return chamber 31 also includes a second outer drainage wall 34 connected to the second oil return chamber bottom surface 33 and distributed opposite to the second inner drainage wall 32. The second outer drainage wall 34 is inclined from top to bottom toward the second oil return hole 35.

[0063] As shown in Figure 3, the bottom surface 33 of the second oil return chamber is located at the bottom of the second oil return chamber 31. The oil can flow back into the second oil return chamber 31 and be accommodated on the bottom surface 33. The bottom surface 33 of the second oil return chamber is flat and has a second oil return hole 35 for guiding the oil from the bottom surface 33 of the second oil return chamber into the oil pan 12. The inner wall of the second oil return chamber 31 also includes a second outer drainage wall 34. The second outer drainage wall 34 and the second inner drainage wall 32 are distributed on the outer periphery of the bottom surface 33 of the second oil return chamber, and both the second outer drainage wall 34 and the second inner drainage wall 32 are connected to the bottom surface 33 of the second oil return chamber. The second outer drainage wall 34 is inclined and slopes downward toward the second oil return hole 35 to guide the oil from the outside of the second oil return chamber 31.

[0064] The engine oil in the cylinder block 1 and timing chamber 11 can flow from the outside to the inside along the second outer drain wall 34 to the second oil return chamber 31 and the second oil return hole 35. Combined with the guiding effect of the second inner drain wall 32, the engine oil on the outer periphery of the second oil return chamber 31 is guided in a direction inclined towards the center of the second oil return chamber 31, which can effectively improve the oil return efficiency. It has a simple structure and good guiding effect.

[0065] Therefore, by providing flow guide walls on the outer periphery of both the first oil return chamber 21 and the second oil return chamber 31, the flow direction of the engine oil can be guided, thereby improving the overall oil return efficiency and thus enhancing the overall lubrication efficiency. Furthermore, through the above arrangement, the oil return structure of the engine 100 at both ends is basically the same, which facilitates assembly and arrangement.

[0066] In some embodiments, the bottom surface 23 of the first oil return chamber is provided with an upwardly protruding first oil return chamber oil weir 231. The oil in the first oil return chamber 21 is adapted to be diverted from the first oil return chamber oil weir 231 to flow to the first oil return hole 27 respectively. In this way, a portion of the oil can be guided from the first oil return chamber oil weir 231 into the first oil return hole 27, which can prevent a large amount of oil from accumulating in the first oil return chamber 21 and affecting the oil return speed.

[0067] As shown in Figure 6, the first return oil chamber oil weir 231 is located between the first outer drainage wall 21 and the bottom surface 23 of the first return oil chamber. The first return oil chamber oil weir 231 protrudes upward from the bottom surface 23 of the first return oil chamber, which can increase the flow height of the oil in the first return oil chamber 21. In this way, the engine oil flows into the first return oil chamber 21 through the first outer drainage wall 21, and part of the engine oil flows into the first return oil chamber oil weir 231, which can achieve oil diversion. Furthermore, the flow velocity of the engine oil flowing towards the first return oil hole 27 can be increased by passing through the first return oil chamber oil weir 231, thereby improving the oil flow rate. Its structure is simple and has a good diversion effect.

[0068] In some embodiments, a first oil drain groove 28 and a second oil drain groove 29 are formed at the bottom of the first oil return chamber 21, located on both sides of the first oil return chamber oil weir 231. The oil in the first oil return chamber 21 is adapted to flow to the first oil return hole 27 through the first oil drain groove 28, the first oil return chamber oil weir 231 and the second oil drain groove 29 respectively.

[0069] As shown in Figure 6, in the front-to-back direction, a first oil drain groove 28 and a second oil drain groove 29 are formed at the bottom of the first oil return chamber 21, respectively. The first oil drain groove 28 and the second oil drain groove 29 are connected to the front and rear sides of the oil weir 231 of the first oil return chamber. In this way, the first oil drain groove 28, the oil weir 231 of the first oil return chamber, and the second oil drain groove 29 are distributed sequentially from front to back to achieve the guiding function. Among them, the first oil drain groove 28 and the second oil drain groove 29 can be constructed to be open upwards, which facilitates the flow of oil in the first oil drain groove 28 and the second oil drain groove 29.

[0070] Therefore, through the above-mentioned arrangement, the oil can flow from the first return oil chamber oil weir 231, the first drain oil groove 28 and the second drain oil groove 29 to the first return oil hole 27, which can effectively divert and guide the oil, and improve the oil return rate.

[0071] In some embodiments, the first return oil chamber weir 231 includes a front side 232, an arc surface 233, and a rear side 234, as shown in FIG6. The front side 232 is formed on the side of the first return oil chamber weir 231 facing the first drain groove 28 and is in contact with the inner wall of the first drain groove 28, allowing the front side 232 and the first drain groove 28 to support each other, thus achieving the connection between the first return oil chamber weir 231 and the first drain groove 28. Furthermore, the first drain groove 28 is supported and connected to the inner wall of the first return oil chamber 21, thereby improving the structural strength of the first return oil chamber 21. The arc connection between the front side 232 and the first drain groove 28 further enhances structural strength and ensures a smoother oil flow.

[0072] As shown in Figure 6, the rear side 234 of the first return oil chamber weir is formed on the side of the first return oil chamber weir 231 facing the second oil drain groove 29 and is in contact with the inner wall of the second oil drain groove 29. This allows the rear side 234 of the first return oil chamber weir and the second oil drain groove 29 to support each other, enabling the connection between the first return oil chamber weir 231 and the second oil drain groove 28. The second oil drain groove 28 is also supported and connected to the inner wall of the first return oil chamber 21, thereby improving the structural strength of the first return oil chamber 21. The rear side 234 of the first return oil chamber weir and the second oil drain groove 29 are connected by an arc, which improves structural strength and provides a smooth connection, resulting in more stable oil flow.

[0073] As shown in Figure 6, the first return oil chamber oil weir arc surface 233 is formed on the side of the first return oil chamber oil weir 231 facing the first return oil hole 27, and is supported and connected to the bottom surface 23 of the first return oil chamber in the vertical direction. This allows the first return oil chamber oil weir arc surface 233 and the bottom surface 23 of the first return oil chamber to support each other, which can improve the connection strength between the first return oil chamber oil weir 231 and the bottom surface 23 of the first return oil chamber. Furthermore, there is an arc connection between the first return oil chamber oil weir arc surface 233 and the bottom surface 23 of the first return oil chamber, which can improve the structural strength and make the structural connection smooth, resulting in more stable oil flow.

[0074] In this design, the first return oil chamber oil weir arc surface 233 is set to be arc-shaped, and the front side 232 and the rear side 234 of the first return oil chamber oil weir can be set to extend in the left and right direction. The first return oil chamber oil weir arc surface 233 can be set to be 40% to 60% of the width of the first return oil chamber 21. A gap is formed between the front side 232 and the rear side 234 of the first return oil chamber oil weir, which can increase the width of the return oil section by more than 2 times to improve the return oil speed.

[0075] Furthermore, by setting the front side 232, the arc surface 233, and the rear side 234 of the first return oil chamber oil weir, the first return oil chamber oil weir 231 protrudes from the bottom surface 23 of the first return oil chamber, and a height difference is formed between the two, with the height difference being within the range of 3mm to 5mm. This allows the oil to form a drop between the top of the first return oil chamber oil weir 231 and the bottom surface 23 of the first return oil chamber, thereby increasing the flow rate of the engine oil to the first return oil hole 27.

[0076] It should also be noted that if the height between the first return oil chamber oil weir 231 and the bottom surface 23 of the first return oil chamber is too high, it may cause a "hydraulic jump" effect, causing the oil to flow back and agitate, increasing speed loss. The distance between the first return oil chamber oil weir 231 and the first return oil hole 27 should be in the range of 3mm to 6mm. The shorter the distance, the better it is to reduce friction resistance. However, if the distance is too short, it will not be conducive to the smooth transition of the oil from the first return oil chamber oil weir 231 to the first return oil hole 27.

[0077] In some embodiments, the first outer drainage wall 24 includes a first drainage front arc surface 241 and a first drainage rear arc surface 242 connected together. The first drainage front arc surface 241 extends to connect with the first oil drain groove 28 and is adapted to guide the flow toward the first oil drain groove 28. The first drainage rear arc surface 242 extends to connect with the second oil drain groove 29 and is adapted to guide the flow toward the second oil drain groove 29.

[0078] The first front arc surface 241 of the first drain is connected to the first oil drain groove 28, allowing the oil to flow along the first front arc surface 241 to the first oil drain groove 28. The first rear arc surface 242 of the first drain is connected to the second oil drain groove 29, allowing the oil to flow along the first rear arc surface 242 to the second oil drain groove 29. Thus, by setting the first front arc surface 241 and the first rear arc surface 242 of the first drain, the width of the return oil section can be increased by more than 50%. When the oil passes through the first outer drain wall 24, the first front arc surface 241 and the first rear arc surface 242 guide the oil to flow to both sides, reducing the return oil burden.

[0079] Due to gravity, the amount of oil in the center of the first outer drainage wall 24 is greater than that on both sides. By setting the first return oil chamber oil weir 231, the oil flow rate in the center can be increased. In addition, the oil flow rate can be made faster by combining the first oil drain groove 28 and the second oil drain groove 29 to guide the oil.

[0080] As shown in Figure 6, in the front-back direction, the first drainage front arc surface 241 is formed on the front side of the first oil return cavity 21, and the first drainage rear arc surface 242 is formed on the rear side of the first oil return cavity 21. Both the first drainage front arc surface 241 and the first drainage rear arc surface 242 can be constructed as arc surfaces, which are simple in structure and easy to process.

[0081] In some embodiments, the inner wall of the first oil return cavity 21 is further provided with a first inner side edge surface 25 connected above the first inner drainage wall 22. The first inner side edge surface 25 is configured to slope from top to bottom close to the bottom surface 23 of the first oil return cavity, and the inclination angle of the first inner side edge surface 25 relative to the bottom surface 23 of the first oil return cavity is A1, and satisfies: 10°≤A1≤30°.

[0082] The inner wall of the first oil return chamber 21 is also provided with a first inner side edge surface 25, which is connected to the upper end of the first inner drainage wall 22. The first inner side edge surface 25 is constructed as an inclined surface and slopes from top to bottom towards the bottom surface 23 of the first oil return chamber to realize the drainage of engine oil inside the timing chamber 11. Moreover, the structure is simple and easy to process.

[0083] As shown in Figures 1 and 2, the inclination angle of the first inner edge surface 25 relative to the bottom surface 23 of the first oil return chamber can be 10°, 15°, 20°, 25°, 30°, etc. By setting these values, the oil inside the cylinder 1 can flow from the inside to the outside along the first inner edge surface 25 and the first inner guide wall 22 to the first oil return chamber 21. During the flow, the gravitational potential energy of the oil can be quickly converted into kinetic energy, so that the oil can be quickly discharged into the first oil return chamber 21. If the inclination angle is too small, it will not be conducive to guiding the oil in the cylinder 1 to be discharged quickly. If the inclination angle is too large, the edge of the first oil return chamber 21 will form a thin, sharp corner, resulting in insufficient structural strength. Moreover, the inclination angle of the first inner edge surface 25 relative to the bottom surface 23 of the first oil return chamber is not limited to those listed in this embodiment, and can be selectively set according to the actual space and structural characteristics.

[0084] Furthermore, a transition arc is provided at the connection between the first inner edge surface 25 and the first inner drainage wall 22, which can make the connection between the two smooth and improve the stability of oil flow.

[0085] In some other embodiments, the inner wall of the first oil return cavity 21 is also provided with a first outer edge surface 26 connected to the upper part of the first outer drainage wall 24. The first outer edge surface 26 is higher than the bottom surface 23 of the first oil return cavity, and the height difference between the first outer edge surface 26 and the bottom surface 23 of the first oil return cavity is L1, which satisfies: 15mm≤L1≤30mm.

[0086] The inner wall of the first oil return chamber 21 is also provided with a first outer edge surface 26. The first outer edge surface 26 is connected to the upper end of the first outer drainage wall 24. The first outer edge surface 26 can be constructed as a plane, and the first outer edge surface 26 needs to be higher than the bottom surface 23 of the first oil return chamber, that is, a height difference is formed between the two, which can form an oil storage space between them. At the same time, the bottom surface 23 of the first oil return chamber is lower, so as to realize the sinking setting of the first oil return chamber 21. In this way, under the motion inertia of the timing chain 6 on the right side and the gravity of the oil, the first outer edge surface 26 and the oil on its outside are quickly guided to the bottom surface 23 of the first oil return chamber to improve the oil return effect.

[0087] The height between the first outer edge surface 26 and the bottom surface 23 of the first oil return chamber can be set to 15mm, 18mm, 20mm, 25mm, 30mm, etc. By setting these values, there is sufficient vertical space between the first outer edge surface 26 and the bottom surface 23 of the first oil return chamber, thereby increasing the oil storage capacity of the first oil return chamber 21. Furthermore, when the engine 100 is operating at high speed and high load, a large flow of oil can be quickly discharged into the first oil return chamber 21, preventing the timing chain 6 from churning the oil and improving the operational reliability of the engine 100. The height difference between the bottom surface 23 of the first oil return chamber and the first outer edge surface 26 is not limited to those listed in this embodiment and can be selectively set according to actual space and structural characteristics.

[0088] Furthermore, if the height difference between the bottom surface 23 of the first oil return chamber and the first outer edge surface 26 is too small, the effect of gravity-driven oil flow in the first cylinder head 2 will be poor. If the height difference between the bottom surface 23 of the first oil return chamber and the first outer edge surface 26 is too large, the inlet horizontal height of the first oil return hole 27 needs to be low, which is not conducive to the formation of a height difference between the first oil return hole 27 and the oil surface of the oil pan 12, resulting in poor oil flow and hindering oil return.

[0089] It should also be noted that the first outer edge surface 26 can be constructed as an inclined surface, and the first outer edge surface 26 and the bottom surface 23 of the first oil return chamber form an angle in the range of 20° to 30°. The connection between the first outer edge surface 26 and the first outer drain wall 24 is provided with an arc. By setting the angle, the gravitational potential energy of the oil entering the first oil return chamber 21 can be quickly converted into kinetic energy to increase the flow rate of the oil to the first outer drain wall 24.

[0090] In some embodiments, the first outer drainage wall 24 is constructed as an inclined curved surface, and the slope of the inclined curved surface gradually increases from top to bottom and then gradually decreases. That is, the inclination of the first outer drainage wall 24 gradually increases from small to small and then gradually decreases, which can guide the flow rate of the engine oil to gradually increase from small to small and then gradually decrease, and can quickly draw away the engine oil at the first outer edge surface 26 and the engine oil on the outside.

[0091] As shown in Figure 2, in the longitudinal sectional view, the inclined surface can include three segments. The slope of the first segment gradually increases, the slope of the second segment remains constant, and the slope of the third segment gradually decreases. The convex directions of the first and third segments are opposite; the first segment convexes towards the center of the first oil return chamber 21, while the third segment convexes away from the center of the first oil return chamber 21. This allows the slope of the inclined surface to gradually steepen and then gradually decrease, enabling the oil to first accelerate smoothly, then increase its flow rate, and finally decrease its flow rate, thereby reducing the impact on the bottom surface 23 of the first oil return chamber and improving the oil flow rate. Furthermore, the structure is simple, reasonable, and has a good drainage effect.

[0092] As shown in Figures 1 and 2, the tilt angle of the inclined surface relative to the horizontal direction is A2, and satisfies: 30°≤A2≤60°. That is, in actual design, the tilt angle of the inclined surface relative to the horizontal direction can be set to gradually increase from 30° to 60°, and then gradually decrease from 60° to 30°, so as to realize the tilt angle setting of the inclined surface. The tilt angle can be 30°, 35°, 40°, 45°, 50°, 60°, etc. This setting can make the slope of the inclined surface continuous. Moreover, the tilt angle of the inclined surface relative to the horizontal direction is not limited to that described in this embodiment, and can be selected and set according to actual needs.

[0093] Furthermore, if the tilt angle of the inclined surface relative to the horizontal direction is too small, the oil flow rate will be relatively low. On the one hand, it is not conducive to the rapid flow of oil to the oil pan 12, and on the other hand, it is not conducive to the flow of oil when the engine 100 is tilted to the right. If the tilt angle of the inclined surface relative to the horizontal direction is too large, it will increase the space size and weight of the first oil return chamber 21 of the first cylinder head 2 on the right side, which is not conducive to improving system integration.

[0094] In some embodiments, the first external drainage wall 24 is tilted at an angle of A2 relative to the horizontal direction, and the second external drainage wall 34 is tilted at an angle of A3 relative to the horizontal direction, and satisfies: (A3-A2) / A2≥0.1.

[0095] The structures of the first return oil chamber 21 and the second return oil chamber 31 are basically the same. As shown in Figures 1-3, both the first external drainage wall 24 and the second external drainage wall 34 are inclined structures, but their inclination angles are different. The inclination angle of the second external drainage wall 34 relative to the horizontal direction can be set to be greater than or equal to the inclination angle of the first external drainage wall 24 relative to the horizontal direction, and can be greater than or equal to 10% of the inclination angle of the first external drainage wall 24. For example, when the inclination angle of the first external drainage wall 24 is 50°, the minimum inclination angle of the second external drainage wall 34 can be set to 55°. The inclination angle of the second external drainage wall 34 can also be set to 56°, 60°, etc. The setting is not limited to that described in this embodiment and can be selectively set according to actual needs.

[0096] In other embodiments, the first inner drainage wall 22 is tilted at an angle of A4 relative to the horizontal direction, and the second inner drainage wall 32 is tilted at an angle of A5 relative to the horizontal direction, satisfying: (A5-A4) / A4≥0.1.

[0097] As shown in Figures 1-3, both the first inner drainage wall 22 and the second inner drainage wall 32 are inclined structures, but their inclination angles are different. The inclination angle of the second inner drainage wall 32 relative to the horizontal direction can be set to be greater than or equal to the inclination angle of the first inner drainage wall 22 relative to the horizontal direction, and can be greater than or equal to 10% of the inclination angle of the first inner drainage wall 22. For example, when the inclination angle of the first inner drainage wall 22 is 50°, the minimum inclination angle of the second inner drainage wall 32 can be set to 55°, and the inclination angle of the second inner drainage wall 32 can also be set to 56°, 60°, etc. The setting is not limited to that described in this embodiment and can be selectively set according to actual needs.

[0098] Therefore, by setting the inclination angle of the second outer drainage wall 34 relative to the horizontal direction to satisfy the condition (A3-A2) / A2≥0.1 with respect to the inclination angle of the first outer drainage wall 24 relative to the horizontal direction, the guiding effect of the second outer drainage wall 34 can be made greater than that of the first outer drainage wall 24. Furthermore, by setting the inclination angle of the second inner drainage wall 32 relative to the horizontal direction to satisfy the condition (A5-A4) / A4≥0.1 with respect to the inclination angle of the first inner drainage wall 22 relative to the horizontal direction, the guiding effect of the second inner drainage wall 32 can be made greater than that of the first inner drainage wall 22. In this way, when the engine oil is carried to the left side of the engine 100 by the timing chain 6, the oil return difficulty of the second oil return chamber 31 on the left side can be improved through the above structural settings, so as to effectively balance the oil return efficiency on the left and right sides of the engine 100 and improve the lubrication capacity of the whole machine.

[0099] In some embodiments, as shown in Figures 1 and 2, the inclination angle of the first inner guide wall 22 relative to the horizontal direction is A4, and satisfies: 25°≤A4≤70°. That is, in actual design, the inclination angle of the first inner guide wall 22 relative to the horizontal direction can be set to 25°, 30°, 35°, 40°, 45°, 50°, 60°, 70°, etc. By setting the above values, the oil inside the cylinder block 1 can flow from the inside to the outside along the first inner guide wall 22 to the first oil return chamber 21, so that the oil can be quickly discharged into the first oil return chamber 21. The inclination angle of the first inner guide wall 22 relative to the horizontal direction is not limited to those listed in this embodiment, and can be selectively set according to the actual space and structural characteristics. Moreover, the inclination angle of the first inner guide wall 22 can be greater than the inclination angle of the first outer guide wall 24. In this way, the oil carried by the timing chain 6 on the left side can quickly flow along the first inner guide wall 22 to the first oil return chamber 21, improving the oil return efficiency on the right side of the engine 100.

[0100] It should be noted that if the tilt angle of the first inner drain wall 22 is too small, the oil flow rate will be low. On the one hand, it is not conducive to the rapid flow to the oil pan 12, and on the other hand, it is not conducive to the flow of oil when the engine 100 is tilted to the left. If the tilt angle of the first inner drain wall 22 is too large, it will increase the space size and weight of the first oil return chamber 21 on the right side, which is not conducive to improving system integration.

[0101] In some embodiments, the bottom of the first cylinder head 2 is connected to a first oil return pipe 4, and the first oil return hole 27 is connected to the oil pan 12 through the first oil return pipe 4. In this way, the engine oil in the first cylinder head 2 can flow back to the oil pan 12 through the first oil return pipe 4.

[0102] The bottom of the first cylinder head 2 and the cylinder block 1 define the first oil return chamber 21. The first oil return chamber 21 is connected to the upper end of the first oil return pipe 4 through the first oil return hole 27, and the lower end of the first oil return pipe 4 is connected to the oil pan 12. In this way, the first oil return chamber 21 can be connected to the oil pan 12 through the external first oil return pipe 4, so that the engine oil in the timing chamber 11 flows to the oil pan 12 through the first oil return chamber 21 and the first oil return pipe 4, thereby realizing the collection of engine oil in the first cylinder head 2 and the cylinder block 1.

[0103] In other embodiments, the bottom of the second cylinder head 3 is connected to a second oil return pipe 5, and the second oil return hole 35 is connected to the oil pan 12 through the second oil return pipe 5. In this way, the engine oil in the second cylinder head 3 can flow back to the oil pan 12 through the second oil return pipe 5.

[0104] The bottom of the second cylinder head 3 and the cylinder block 1 define the second oil return chamber 31. The second oil return chamber 31 is connected to the upper end of the second oil return pipe 5 through the second oil return hole 35, and the lower end of the second oil return pipe 5 is connected to the oil pan 12. In this way, the second oil return chamber 31 can be connected to the oil pan 12 through the external second oil return pipe 5, so that the engine oil in the timing chamber 11 flows to the oil pan 12 through the first oil return chamber 21 and the first oil return pipe 4, thereby realizing the collection of engine oil in the first cylinder head 2 and the cylinder block 1.

[0105] Therefore, by setting an external first oil return pipe 4 between the first oil return chamber 21 and the oil pan 12, and setting an external second oil return pipe 5 between the second oil return chamber 31 and the oil pan 12, the oil in the first oil return chamber 21 and the second oil return chamber 31 can be directly introduced into the oil pan 12 without passing through the inside of the cylinder block 1, which improves the structural responsiveness, effectively avoids the risk of low oil pressure, and ensures that the whole machine has good lubrication performance.

[0106] Furthermore, the externally mounted first oil return pipe 4 and second oil return pipe 5 can reduce the connection problems of the first cylinder head 2, the second cylinder head 3 and the oil pan 12, and the first cylinder head 2, the second cylinder head 3 and the cylinder block 1 do not need to be equipped with oil return channels, which reduces weight and cost, and reduces the space size of the two cylinder heads and the cylinder block 1, leaving space to arrange other components, which greatly improves the integration of the engine 100.

[0107] In some embodiments, the outlet end of the second return oil pipe 5 is higher than the outlet end of the first return oil pipe 4, and the height difference between the outlet end of the second return oil pipe 5 and the outlet end of the first return oil pipe 4 is L2, which satisfies: 30mm≤L2≤45mm.

[0108] The outlet ends of both the second return oil pipe 5 and the first return oil pipe 4 are connected to the oil pan 12, as shown in Figure 1. In the vertical direction, the outlet end of the first return oil pipe 4 is positioned higher than the outlet end of the first return oil pipe 5. The height difference between them can be 30mm, 35mm, 40mm, 45mm, etc. By setting these values, the return oil capacity of the first return oil pipe 4 and the second return oil pipe 5 can be different to adapt to different operating conditions of the engine 100. Furthermore, the height difference between the outlet ends of the second return oil pipe 5 and the first return oil pipe 4 is not limited to those listed above and can be selected according to actual needs.

[0109] The engine 100 operates under two conditions: high-speed driving and stationary revving. Both conditions are real based on driving habits, especially the stationary revving condition. When stationary, the engine 100 tilts to the left with the vehicle, lowering the horizontal level of the outlet of the second return oil pipe 5 while raising the horizontal level of the outlet of the first return oil pipe 4. According to hydraulic principles, fluid pressure increases with depth, increasing the return oil resistance of the left-side second return oil pipe 5. Furthermore, the clockwise rotation of the timing chain 6 causes the return oil volume on the left side of the engine 100 to be greater than that on the right. By setting the outlet end of the second return oil pipe 5 higher than the outlet end of the first return oil pipe 4, the horizontal height of the outlet end of the second return oil pipe 5 is close to that of the outlet end of the first return oil pipe 4 when the vehicle is stationary. This reduces the difference in return oil resistance caused by the difference in liquid pressure at the outlet of the return oil pipe. At the same time, the increased horizontal height of the outlet end of the first return oil pipe 4 can appropriately weaken the return oil capacity on the right side, reduce the rate at which the oil level rises in the cylinder block 1, and lower the liquid pressure at the outlet end of the second return oil pipe 5, which is beneficial for the return oil on the left side of the engine 100.

[0110] Therefore, through the above settings, the left side of the engine 100 can have better oil return capability than the right side of the engine 100 when the engine is stationary and the throttle is revved. Furthermore, the oil return structure of this embodiment is adapted to the lubrication needs of the engine 100 under different operating conditions, thereby improving the working performance of the engine 100.

[0111] In other embodiments, the extension direction of the first return oil pipe 4 is inclined at an angle of B1 relative to the horizontal plane, and satisfies: B1≥30°, and the extension direction of the second return oil pipe 5 is inclined at an angle of B2 relative to the horizontal plane, and satisfies: B2≥30°.

[0112] As shown in Figure 1, the first oil return pipe 4 extends in an inclined direction, and the inclination angle relative to the horizontal plane is set to B1. The inclination angle of the first oil return pipe 4 can be set to 30°, 35°, 40°, etc. By setting these values, the oil can flow back from the first oil return chamber 21 to the oil pan 12 in an inclined direction. The larger the inclination angle, the smoother the oil return is due to gravity. This ensures that the oil return function at the first cylinder head 2 is normal when the vehicle is tilted at low speed, improves the oil return efficiency on the right side of the engine 100, and ensures the normal operation of the vehicle.

[0113] The second oil return pipe 5 is the same as the first oil return pipe 4, extending in an inclined direction. The second oil return pipe 5 and the first oil return pipe 4 extend inclined towards each other. The inclination angle of the second oil return pipe 5 relative to the horizontal plane is set to B2. The inclination angle of the second oil return pipe 5 can be set to 30°, 35°, 40°, etc. By setting these values, the oil can flow back from the second oil return chamber 31 to the oil pan 12 in an inclined direction. The larger the inclination angle, the smoother the oil return is due to gravity. This ensures that the oil return function at the second cylinder head 3 is normal when the vehicle is tilted at low speed, thus improving the oil return efficiency on the right side of the engine 100.

[0114] The first return oil pipe 4 and the second return oil pipe 5 can have the same or different inclination angles relative to the horizontal plane, and their inclination angles are not limited to those listed above. They can be selectively set according to actual needs.

[0115] In some embodiments, the outlet end of the first return pipe 4 is configured to open inward to connect with the oil pan 12, and the outlet end of the second return pipe 5 is configured to open backward to connect with the oil pan 12.

[0116] As shown in Figure 1, the outlet end of the first oil return pipe 4 extends inward and opens inward, and the oil pan 12 is provided with an outward-opening right oil return port 121, so that the outlet end of the first oil return pipe 4 is connected to the right oil return port 121 in the left-right direction, and the right oil return port 121 is lower than the first oil return chamber 21. In this way, the oil in the first oil return chamber 21 can flow downward along the first oil return pipe 4 and flow into the oil pan 12 from the outside to the inside, realizing the rapid return of the right oil.

[0117] As shown in Figure 1, the outlet end of the second oil return pipe 5 extends to the rear and opens to the rear, and the oil pan 12 is provided with a left oil return port 122 that opens to the front, so that the outlet end of the second oil return pipe 5 is connected to the left oil return port 122 in the front-rear direction, and the left oil return port 122 is lower than the second oil return chamber 31. In this way, the oil in the second oil return chamber 31 can flow downward along the second oil return pipe 5 and flow into the oil pan 12 from front to back, realizing the rapid return of the oil on the left side.

[0118] According to the oil pump speed-flow curve, the oil flow rate is directly proportional to the engine speed of 100. That is, the oil flow rate increases as the engine speed of 100 increases. When the engine 100 is stationary, the kickstand is usually lowered and located on the left side of the vehicle. At this time, the vehicle is in a left-low-right-high posture. The engine 100 tilts to the left with the vehicle, and the horizontal height of the outlet end of the second oil return pipe 5 decreases. The lowest point of the second oil return pipe 5 shifts from the outlet end to the inlet end, and a negative height difference is formed between the outlet end and the lowest point of the second oil return pipe 5, thus obstructing gravity oil return.

[0119] In this embodiment, the outlet end of the second oil return pipe 5 is set to be open to the rear. Compared with the conventional method of designing the cylinder block 1 interface as a ramp shape, the rearward opening setting can fundamentally avoid the possibility of a negative height difference between the outlet end of the second oil return pipe 5 and the oil pan 12, eliminating the oil return resistance of the second oil return pipe 5. On the other hand, it can prevent the oil discharged from the oil return port 122 on the left side of the cylinder block 1 from forming an opposition with the oil thrown out by the rotation of the transmission gears, reducing the oil return resistance caused by the opposition of the two oil streams. Moreover, the structure is simple and will not increase the volume and weight of the cylinder block 1 interface structure, which is conducive to compact design. In addition, the above settings can improve the performance of the engine 100 under different working conditions.

[0120] In some embodiments, the bottom of the first oil return chamber 21 is provided with a first oil return hole 27, the upper end of the first oil return pipe 4 is detachably installed at the first oil return hole 27 through a first connector 412, and a first sealing member 43 is provided between the first oil return pipe 4 and the inner wall of the first oil return hole 27.

[0121] As shown in Figure 2, the bottom of the first oil return chamber 21 is provided with a first oil return hole 27 that extends through in the vertical direction. The upper end of the first oil return pipe 4 extends into the first oil return hole 27. As shown in Figure 4, the upper end of the first oil return pipe 4 is provided with a first connecting joint 41. The first connecting joint 41 is provided with a first connecting hole 411. Correspondingly, the first cylinder head 2 is provided with a second connecting hole that extends in the vertical direction. The second connecting hole and the first connecting hole 411 are used to pass through the first connecting member 412. The upper end of the first oil return pipe 4 is provided with a first mounting groove 42 for installing the first sealing member 43. The first mounting groove 42 is recessed toward the axis of the first oil return pipe 4.

[0122] In practical design, the first sealing element 43 can be set as an O-ring, and the first connecting element 412 is a connecting bolt. During installation, the first sealing element 43 is fitted into the first mounting groove 42, and the upper end of the first oil return pipe 4 extends into the first oil return hole 27. The first connecting element 412 is inserted into the first connecting hole 411 and threadedly connected to the second connecting hole, which can achieve a reliable connection between the first oil return pipe 4 and the first oil return cavity 21. By setting the first sealing element 43, the first sealing element 43 can be press-fitted with the inner wall of the first oil return hole 27 and the first mounting groove 42 of the first oil return pipe 4, making the seal between the first oil return pipe 4 and the first oil return cavity 21 more reliable. Among them, the connecting bolt can be selected from M5 to M8, which can meet the fastening requirements of the first oil return pipe 4 while minimizing the structural size and weight of the first oil return pipe 4 and the first oil return cavity 21.

[0123] Furthermore, a second connecting joint 44 is provided at the outlet end of the first return oil pipe 4. The connecting joint also has two connecting holes for threaded connection with the oil pan 12. A right-side sealing gasket 45 is provided on the second connecting joint 44, which has a metal corrugated sealing rib. The right-side sealing gasket 45 is tightly fitted with the flange face of the first return oil pipe 4 and the right-side return oil port 121. The first return oil pipe 4 is connected to the oil pan 12 by two connecting bolts. The connection is reliable and the sealing performance is good.

[0124] The sealing force generated by the mutual pressure between the first seal 43 and the inner wall of the first oil return hole 27 is at least 6 times the liquid pressure inside the first oil return cavity 21. After the first seal 43 is engaged with the first mounting groove 42, it has sufficient compression ratio and filling ratio to effectively improve the sealing performance of the first seal 43.

[0125] It should also be noted that the inner diameter of the first oil return pipe 4 is generally set to 12mm to 20mm, i.e., it can be set to 12mm, 14mm, 16mm, 18mm, 20mm, etc. Setting it within this range facilitates the rapid flow of engine oil through the first oil return pipe 4, improving oil return efficiency. If the diameter of the first oil return pipe 4 is too small, it will result in insufficient oil return capacity, and may even lead to insufficient oil circulation in the engine. Furthermore, if the diameter of the first oil return pipe 4 is too large, it will not only increase the weight of the first oil return pipe 4, but also encroach on the space for other components, which is detrimental to improving system integration.

[0126] Furthermore, the diameter of the first seal 43 is usually 20% larger than the inner diameter of the first return oil pipe 4, i.e., it can be set to 17mm. The wire diameter of the first seal 43 is generally 10% to 20% of its diameter, usually selected as 2mm to 3mm, which can improve the sealing compression performance of the first seal 43. However, if the wire diameter of the first seal 43 is too small, it will not be able to generate sufficient compression of the rubber, which is not conducive to sealing. If the wire diameter of the first seal 43 is too large, it will increase the size of the first mounting groove 42 and other related structures, which is not conducive to structural compactness.

[0127] It should also be noted that the compression ratio is the ratio of the compression deformation of the first seal 43 to the wire diameter. The groove depth of the first mounting groove 42 is used to limit the compression ratio. The groove depth of the first mounting groove 42 can be set to be 20% to 30% smaller than the wire diameter of the first seal 43, with an optimal value of 25%. The higher the compression ratio, the more reliable the seal. Of course, the compression ratio cannot be set too high, as this will increase the elastic deformation of the first seal 43 and reduce its service life. The filling ratio is the ratio of the cross-sectional area of ​​the first seal 43 to the cross-sectional area of ​​the first mounting groove 42, usually set between 70% and 95%, with an optimal value of 85%. The product of the groove depth and the groove width of the first mounting groove 42 is the cross-sectional area of ​​the first mounting groove 42. In actual design, the target filling ratio is obtained by limiting these two dimensions. The higher the filling ratio, the greater the friction between the first seal 43 and the first mounting groove 42, and the better the sealing performance. However, it cannot be set too high, as this will cause uneven stress on the first seal 43, leading to deformation and damage to the first seal 43.

[0128] In other embodiments, the bottom of the second oil return chamber 31 is provided with a second oil return hole 35, the upper end of the second oil return pipe 5 is detachably installed at the second oil return hole 35 through a second connector 512, and a second sealing member 53 is provided between the second oil return pipe 5 and the inner wall of the second oil return hole 35.

[0129] As shown in Figure 3, the bottom of the second oil return chamber 31 is provided with a second oil return hole 35 that extends through in the vertical direction. The upper end of the second oil return pipe 5 extends into the second oil return hole 35. As shown in Figure 5, the upper end of the second oil return pipe 5 is provided with a third connecting joint 51. The third connecting joint 51 is provided with a third connecting hole 511. Correspondingly, the second cylinder head 3 is provided with a fourth connecting hole that extends in the vertical direction. The third connecting hole 511 and the fourth connecting hole are used to pass through the second connecting member 512. The upper end of the second oil return pipe 5 is provided with a second mounting groove 52 for installing the second sealing member 53. The second mounting groove 52 is recessed toward the axis of the second oil return pipe 5.

[0130] In practical design, the second sealing element 53 can be set as an O-ring, and the second connecting element 512 is a connecting bolt. During installation, the second sealing element 53 is fitted into the second mounting groove 52, and the upper end of the second oil return pipe 5 extends into the second oil return hole 35. The second connecting element 512 is inserted into the third connecting hole 511 and threadedly connected to the fourth connecting hole, which can achieve a reliable connection between the second oil return pipe 5 and the second oil return cavity 31. By setting the second sealing element 53, the second sealing element 53 can be press-fitted with the inner wall of the second oil return hole 35 and the second mounting groove 52 of the second oil return pipe 5, making the seal between the second oil return pipe 5 and the second oil return cavity 31 more reliable. Among them, the connecting bolt can be selected from M5 to M8, which can meet the fastening requirements of the second oil return pipe 5 while minimizing the structural size and weight of the second oil return pipe 5 and the second oil return cavity 31.

[0131] Furthermore, a fourth connecting joint 54 is provided at the outlet end of the second return oil pipe 5. The fourth connecting joint 54 also has two connecting holes for threaded connection with the oil pan 12. A left sealing gasket 55 is provided on the fourth connecting joint 54, which has a metal corrugated sealing rib. The left sealing gasket 55 is tightly fitted with the flange face of the second return oil pipe 5 and the left return oil port 122. The second return oil pipe 5 is connected to the oil pan 12 by two connecting bolts. The connection is reliable and the sealing performance is good.

[0132] It should be noted that the first oil return pipe 4 is a thin-walled metal pipe with a corrugated section 46. The corrugated section 46 structure has a certain amount of deformability. Since both ends of the first oil return pipe 4 are rigidly connected to the first cylinder head 2 and the cylinder block 1, the corrugated pipe can reduce stress concentration through slight deformation, which is beneficial to the sealing between the first seal 43 and the first oil return hole 27. The second oil return pipe 5 has the same structural arrangement as the first oil return pipe 4, which can also improve the sealing between the second seal 53 and the second oil return hole 35. The first oil return pipe 4 is provided with one corrugated section 46 structure, and the second oil return pipe 5 is provided with three corrugated sections 46.

[0133] Furthermore, the wall thickness of the corrugated section 46 of the first return oil pipe 4 and the second return oil pipe 5 is generally set between 0.4 and 1.0 mm, with 0.6 mm being optimal. If the wall thickness of the corrugated section 46 is too thin, the structure will be weak and prone to cracking under the vibration of the engine. If the wall thickness of the corrugated section 46 is too thick, it will not be conducive to the large deformation of the corrugated section 46, and the corrugation will be difficult to form and have poor processability, which will also be detrimental to the overall weight reduction of the engine. In addition, the length of the first return oil pipe 4 is usually between 220 and 280 mm. If its length is too long, the oil will lose too much heat from the external environment, and there is a risk of oil emulsification when the engine is cold-started at 100 km / h in northern winters. If the length is too short, an effective height difference cannot be formed, which is not conducive to gravity oil return.

[0134] This application also proposes a vehicle.

[0135] According to the vehicle of the present application embodiment, an engine 100 of any of the above embodiments is provided. By providing a sunken first oil return chamber 21, an external first oil return pipe 4, a sunken second oil return chamber 31 and an external second oil return pipe 5 on both sides of the engine 100, the oil return efficiency on both sides of the engine 100 can be improved respectively. This can avoid the formation of oil dead zones in the first cylinder head 2 and the second cylinder head 3, and will not affect the circulating oil volume of the lubrication system, saving the amount of oil added. It can also prevent the timing chain 6 from stirring the oil, reduce the amount of oil and gas, reduce the burden on the crankcase ventilation system, and allow the oil to be directly introduced into the oil pan 12. This can reduce the setting of the built-in oil return channel, reduce weight and cost. Furthermore, by setting the inclination angle of the second inner drain wall 32 to be greater than the inclination angle of the first inner drain wall 22, the oil return efficiency on the left and right sides of the engine 100 can be balanced, so that the whole machine has good lubrication performance.

[0136] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0137] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. An engine, wherein, include: Cylinder (1), a timing chamber (11) is formed inside the cylinder (1), and an oil pan (12) is provided below the timing chamber (11). A first cylinder head (2) and a second cylinder head (3) are installed opposite each other on both sides of the cylinder body (1). The first cylinder head (2) and the cylinder body (1) define a first oil return chamber (21) that communicates with the timing chamber (11). The second cylinder head (3) and the cylinder body (1) define a second oil return chamber (31) that communicates with the timing chamber (11). The bottom of the first oil return chamber (21) is provided with a first oil return hole (27) that communicates with the oil pan (12). The bottom of the second oil return chamber (31) is provided with a second oil return hole (35) that communicates with the oil pan (12). The timing chain (6) in the cylinder body (1) is adapted to drive at least a portion of the engine oil to flow toward the second oil return chamber (31). In the first oil return chamber (21), a first inner guide wall (22) is formed on the side near the cylinder body (1). The first inner guide wall (22) is inclined from top to bottom toward the first oil return hole (27). In the second oil return chamber (31), a second inner guide wall (32) is formed on the side near the cylinder body (1). The second inner guide wall (32) is inclined from top to bottom toward the second oil return hole (35). The angle of inclination of the second inner guide wall (32) relative to the horizontal direction is greater than the angle of inclination of the first inner guide wall (22) relative to the horizontal direction.

2. The engine according to claim 1, wherein, The bottom of the first oil return chamber (21) is formed with a first oil return chamber bottom surface (23), the first oil return hole (27) is provided on the first oil return chamber bottom surface (23), and the inner wall of the first oil return chamber (21) also includes a first outer drainage wall (24) connected to the first oil return chamber bottom surface (23) and distributed opposite to the first inner drainage wall (22). The first outer drainage wall (24) is inclined from top to bottom toward the first oil return hole (27); And / or, the bottom of the second oil return chamber (31) is formed with a second oil return chamber bottom surface (33), the second oil return hole (35) is provided on the second oil return chamber bottom surface (33), and the inner wall of the second oil return chamber (31) also includes a second outer drainage wall (34) connected to the second oil return chamber bottom surface (33) and distributed opposite to the second inner drainage wall (32). The second outer drainage wall (34) is inclined from top to bottom toward the second oil return hole (35).

3. The engine according to claim 2, wherein, The bottom surface of the first oil return chamber (21) is provided with an upward protruding first oil return chamber oil weir (231), and the oil in the first oil return chamber (21) is adapted to be diverted from the first oil return chamber oil weir (231) to flow to the first oil return hole (27) respectively.

4. The engine according to claim 3, wherein, The bottom of the first oil return chamber (21) is also formed with a first oil drain groove (28) and a second oil drain groove (29) on both sides of the first oil return chamber oil weir (231). The oil in the first oil return chamber (21) is suitable to flow to the first oil return hole (27) through the first oil drain groove (28), the first oil return chamber oil weir (231) and the second oil drain groove (29) respectively.

5. The engine according to claim 4, wherein, The first return oil chamber oil weir (231) includes a front side (232), an arc surface (233), and a rear side (234). The front side (232) of the first return oil chamber oil weir is formed on the side of the first return oil chamber oil weir (231) facing the first drain groove (28) and is in contact with the inner wall of the first drain groove (28). The rear side (234) of the first return oil chamber oil weir is formed on the side of the first return oil chamber oil weir (231) facing the second drain groove (29) and is in contact with the inner wall of the second drain groove (29). The arc surface (233) of the first return oil chamber oil weir is formed on the side of the first return oil chamber oil weir (231) facing the first return oil hole (27).

6. The engine according to claim 4 or 5, wherein, The first outer drainage wall (24) includes a first drainage front arc surface (241) and a first drainage rear arc surface (242) connected together. The first drainage front arc surface (241) extends to connect with the first oil drain groove (28) and is adapted to guide the flow toward the first oil drain groove (28). The first drainage rear arc surface (242) extends to connect with the second oil drain groove (29) and is adapted to guide the flow toward the second oil drain groove (29).

7. The engine according to any one of claims 2-6, wherein, The inner wall of the first oil return cavity (21) is also provided with a first inner side edge surface (25) connected to the upper part of the first inner drainage wall (22). The first inner side edge surface (25) is set to be inclined from top to bottom close to the bottom surface (23) of the first oil return cavity, and the inclination angle of the first inner side edge surface (25) relative to the bottom surface (23) of the first oil return cavity is A1, and satisfies: 10°≤A1≤30°; And / or, the inner wall of the first oil return cavity (21) is also provided with a first outer edge surface (26) connected above the first outer drainage wall (24). The first outer edge surface (26) is higher than the bottom surface (23) of the first oil return cavity, and the height difference between the first outer edge surface (26) and the bottom surface (23) of the first oil return cavity is L1, and satisfies: 15mm≤L1≤30mm.

8. The engine according to any one of claims 2-7, wherein, The first external drainage wall (24) is constructed as an inclined surface, and the slope of the inclined surface increases gradually from top to bottom and then gradually decreases. Wherein, the tilt angle of the inclined surface relative to the horizontal direction is A2, and satisfies: 30°≤A2≤60°; And / or, the first external drainage wall (24) has an inclination angle of A2 relative to the horizontal direction, and the second external drainage wall (34) has an inclination angle of A3 relative to the horizontal direction, and satisfies: (A3-A2) / A2≥0.1; And / or, the first inner drainage wall (22) has an inclination angle of A4 relative to the horizontal direction, and the second inner drainage wall (32) has an inclination angle of A5 relative to the horizontal direction, and satisfies: (A5-A4) / A4≥0.

1.

9. The engine according to any one of claims 1-8, wherein, The first inner drainage wall (22) has an inclination angle of A4 relative to the horizontal direction, and satisfies: 25°≤A4≤70°.

10. The engine according to any one of claims 1-9, wherein, The bottom of the first cylinder head (2) is connected to the first oil return pipe (4), and the first oil return hole (27) is connected to the oil pan (12) through the first oil return pipe (4); And / or, the bottom of the second cylinder head (3) is connected to a second oil return pipe (5), and the second oil return hole (35) is connected to the oil pan (12) through the second oil return pipe (5).

11. The engine according to claim 10, wherein, The outlet end of the second return oil pipe (5) is higher than the outlet end of the first return oil pipe (4), and the height difference between the outlet end of the second return oil pipe (5) and the outlet end of the first return oil pipe (4) is L2, and satisfies: 30mm≤L2≤45mm.

12. The engine according to claim 10 or 11, wherein, The extension direction of the first return oil pipe (4) is inclined at an angle of B1 relative to the horizontal plane, and satisfies: B1≥30°; The extension direction of the second return oil pipe (5) is inclined at an angle of B2 relative to the horizontal plane, and satisfies: B2≥30°.

13. The engine according to any one of claims 10-12, wherein, The upper end of the first return oil pipe (4) is detachably installed at the first return oil hole (27) via the first connector (412), and a first sealing element (43) is provided between the first return oil pipe (4) and the inner wall of the first return oil hole (27).

14. The engine according to any one of claims 10-12, wherein, The upper end of the second return oil pipe (5) is detachably installed at the second return oil hole (35) via the second connector (512), and a second seal (53) is provided between the second return oil pipe (5) and the inner wall of the second return oil hole (35).

15. A vehicle, wherein, The engine is provided with any one of claims 1-14.

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