Engine exhaust gas circulation structure

Abstract

The invention relates to the technical field of engine waste gas treatment, in particular to an engine waste gas circulation structure which comprises a gas inlet pipe, the end of the gas inlet pipe is sequentially connected with an engine cylinder cover and a crankcase, a filter cavity communicated with the crankcase is formed in the engine cylinder cover, and a grid is arranged on the side, close to the crankcase, of the filter cavity. A cooling pipe is arranged on the other side of the filtering cavity in a penetrating mode, a PVC valve connected with the gas inlet pipe in a penetrating mode is arranged at the top of the cooling pipe and used for directly recycling waste gas in the crankcase, a plurality of through holes are formed in a grid, and a magnetic attraction frame is arranged on the side, away from the crankcase, of the grid. And a protection plate is rotationally arranged at the lower end of the magnetic suction frame, and the protection plate is attached to the magnetic suction frame in a magnetic suction mode and used for anti-reverse treatment of waste gas. The exhaust gas circulation structure and the engine cylinder cover are integrally arranged, the pipe length is shortened, gas leakage is improved, and transmission delay and space occupation are reduced.

Description

Technical Field

[0001] This invention relates to the technical field of engine exhaust gas treatment, specifically to an engine exhaust gas recirculation structure. Background Technology

[0002] An exhaust gas recirculation (EGR) system is a technology that introduces a portion of exhaust gas into the cylinder for combustion, aiming to reduce the peak temperature inside the cylinder and thus decrease nitrogen oxide (NOx) emissions. In motorcycle engine operation, the EGR system plays a crucial role, effectively reducing emissions of harmful gases such as NOx by reintroducing a portion of exhaust gas into the cylinder for combustion. It is a key component in the field of internal combustion engine emission control technology.

[0003] Traditional motorcycle EGR systems are mostly external, with the piping located outside the combustion chamber. The system draws high-temperature exhaust gas from the exhaust pipe, filters and cools it through an external filter and cooler before introducing it into the intake manifold. Exhaust gas from the crankcase is also introduced into the intake manifold after passing through an external PVC valve for fuel exchange, thus recirculating the exhaust gas. This layout is space-constrained in motorcycles, leading to a series of problems. The crankcase-mounted exhaust gas recirculation structure often uses external rubber hoses, which are quite long, causing significant transmission delays and affecting the timeliness of exhaust gas recirculation. This also hinders the engine's dynamic regulation. Furthermore, these external hoses age over time, and the joints may break. Therefore, for these reasons, it is necessary to design a simpler motorcycle engine exhaust gas recirculation structure that shortens exhaust gas transmission time and quickly delivers it to the crankshaft. Summary of the Invention

[0004] The purpose of this invention is to provide an engine exhaust gas recirculation structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: An engine exhaust gas recirculation structure includes an intake pipe, with an engine cylinder head and a crankcase connected sequentially to the end of the intake pipe. The engine cylinder head has a filter chamber that communicates with the crankcase. A grid is provided on one side of the filter chamber near the crankcase, and a cooling pipe is provided on the other side of the filter chamber. A PVC valve that communicates with the intake pipe is provided at the top of the cooling pipe for direct recovery and reuse of exhaust gas in the crankcase.

[0006] Preferably, the grid has several through holes, and a magnetic frame is provided on the side of the grid away from the crankcase. A protective plate is rotatably provided at the lower end of the magnetic frame, and the protective plate is magnetically attached to the magnetic frame for the purpose of preventing backflow of exhaust gas.

[0007] Preferably, the protective plate includes an outer plate rotatably mounted on the grid, an elastic support sheet is provided on the side of the outer plate near the grid, a magnetic layer is provided on the periphery of the elastic support sheet, the elastic support sheet is a high-temperature resistant sealing gasket, and the magnetic layer is a magnetically attracted metal coating.

[0008] Preferably, the outer plate is larger than the through hole, the magnetic layer has the same shape as the magnetic frame, and the magnetic layer is used in conjunction with the magnetic frame.

[0009] Preferably, the filter chamber is provided with a first filter plate and a second filter plate arranged in parallel, the upper ends of the first filter plate and the second filter plate are inclined toward the grid, and a guide plate is inclinedly arranged on the side of the filter chamber near the cooling pipe, the lower end of the guide plate is inclined toward the second filter plate, for collecting unburned particles in the exhaust gas.

[0010] Preferably, both the first filter plate and the second filter plate are provided with through holes, and the through holes on the first filter plate and the second filter plate are staggered. A first collecting plate is provided on the side of the first filter plate away from the grid, and a second collecting plate is provided on the second filter plate on the same side as the first collecting plate and distributed opposite to it. Both the first collecting plate and the second collecting plate are opposite to the through holes for sufficient filtration of exhaust gas.

[0011] Preferably, the first collecting plate has an L-shaped structure and includes a spacer portion connected to the first filter plate. An adjustment portion is provided at the end of the spacer portion, and an inward-retracting piece is provided on the side of the adjustment portion near the first filter plate. The first collecting plate has the same structure as the second collecting plate and is used for adjusting the wind speed of the circulating exhaust gas.

[0012] Preferably, the coefficient of thermal expansion of the adjusting part is greater than that of the inner retracting piece, and the edge end of the inner retracting piece is provided with a limiting ventilation part.

[0013] Preferably, an oil drain valve is provided through the lower end of the filter chamber, the oil drain valve extends to the outside of the engine cylinder head, and the cooling pipe is located close to the intake pipe. The cooling pipe is made of heat dissipation metal material and is used for the circulation and discharge of exhaust gas in the crankcase.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, by setting up the grid, filter chamber and cooling pipe, it is easy to directly integrate the exhaust gas pipe in the crankcase into the inside of the engine cylinder head. The exhaust gas circulation pipe is set up in one piece, shortening the length of the delivery pipe. Then, the delivery of exhaust gas to the intake pipe is controlled by the PVC valve, which can improve the layout defects of the external pipe, increase the exhaust gas circulation rate, and solve the dynamic resistance of the engine. 2. In this invention, by rotating a protective plate on the grid, the exhaust gas recirculation structure can use the magnetic layer on the periphery of the elastic support plate to magnetically attract the grid with the magnetic frame, thus closing the grid. The grid can be opened by the high temperature and high pressure environment of the exhaust gas in the crankcase, allowing the exhaust gas to be discharged. This facilitates the transport of exhaust gas from the crankcase to the intake pipe. At the same time, the exhaust gas recirculation structure can be explosion-proofed to prevent backflow of exhaust gas and increase the safety of the exhaust gas recirculation structure. 3. In this invention, the arrangement of the first and second filter plates in the filter chamber facilitates the filtration of unburned particles and oil in the exhaust gas. The staggered through holes on the first and second filter plates can fully disperse the exhaust gas. Then, by using the different opening directions of the first and second collecting plates, the exhaust gas can be fully filtered, and the oil and unburned particles can be fully filtered. Furthermore, by using the different thermal expansion coefficients of the adjusting part and the inner collecting plate, the exhaust gas delivery rate can be adjusted, and the oil-gas mixing can be improved. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram showing the position and structure of the grid in the engine cylinder head and crankcase in this invention; Figure 3 This is a partial structural cross-sectional view of the grid, filter chamber, and cooling pipe inside the engine cylinder head in this invention; Figure 4 This is a partial structural diagram of the grid in this invention; Figure 5 for Figure 5 Enlarged view of the structure of A in the middle; Figure 6 This is a structural diagram of the first and second filter plates in the filtration chamber of the present invention; Figure 7 This is an exploded view of the structure of the first filter plate and the second filter plate in this invention; Figure 8 This is an enlarged view of the structure of B in 6.

[0016] In the diagram: 1. Intake pipe; 2. Engine cylinder head; 3. Crankcase; 4. Filter chamber; 5. Cooling pipe; 6. Grid; 7. PVC valve; 8. Magnetic frame; 9. Protective plate; 10. Outer plate; 11. Elastic support plate; 12. Magnetic layer; 13. First filter plate; 14. Second filter plate; 15. Through hole; 16. First collection plate; 17. Second collection plate; 18. Spacing part; 19. Adjustment part; 20. Inward retraction plate; 21. Limiting ventilation part; 22. Oil drain valve; 23. Guide plate. Detailed Implementation

[0017] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0018] Please see Figure 1-8 The present invention provides a technical solution: An engine exhaust gas recirculation structure is currently used in motorcycle engines. The exhaust gas recirculation system is mostly set outside the engine. The intake pipe 1 supplies gas to the motorcycle. The gas enters the combustion chamber of the engine cylinder head 2 to provide oxygen for fuel combustion and drive the crankshaft to rotate and do work. Some of the exhaust gas enters the crankcase 3 and is then transmitted back to the intake pipe 1 through the exhaust gas system to realize the recycling of exhaust gas. To improve the exhaust gas pipeline in the existing exhaust gas system, structural modifications were made to the cylinder head. First, a filter chamber 4 was installed in the engine cylinder head 2, with one side of the filter chamber 4 connected to the crankcase 3. Then, a grid 6 was installed on the side of the filter chamber 4 near the crankcase 3. When the crankcase 3 is working, the high-temperature and high-pressure exhaust gas can pass through the grid 6 and directly transfer into the filter chamber 4. Next, a cooling pipe 5 was installed on the other side of the filter chamber 4. The use of cooling materials (such as copper alloy, aluminum alloy, or high thermal conductivity metal-based composite materials) in the cooling pipe 5 can cool the incoming exhaust gas. The exhaust gas temperature at the cooling pipe 5 is lower than that of the high-temperature and high-pressure exhaust gas in the crankcase 3, providing favorable conditions for the transfer of exhaust gas in the crankcase 3. Finally, a PVC valve 7 can be installed at the top of the cooling pipe 5. The material can be nylon + glass fiber or a metal valve body, solving the problem of insufficient high-temperature resistance of the original ordinary PVC material, meeting the exhaust gas temperature conditions of 150-200℃ for motorcycle engines, and ensuring the long-term stability of core components. The output end of PVC valve 7 is connected to the intake pipe 1 to transfer the exhaust gas to the intake pipe 1, directly circulate the exhaust gas in crankcase 3, provide air for the fuel in the combustion chamber, and re-burn the fuel particles in the exhaust gas. This allows for direct recycling of the exhaust gas, solves the problem of exhaust gas transmission delay in the exhaust gas circulation structure, improves the conveying efficiency, reduces the space occupation, avoids damage to the pipeline, and extends the service life of the exhaust gas circulation structure.

[0019] It is worth noting that, during engine operation, to prevent backflow of gas in the engine that could lead to an explosion of the crankcase 3, the grille 6 can be configured as a one-way opening structure; such as Figure 3 and 4 As shown, in some embodiments, the grid 6 has several through holes 15 for exhaust gas to pass into the filter chamber 4. Then, a magnetic frame 8 is set on the side of the grid 6 away from the crankcase 3. A protective plate 9 is rotatably set at the lower end of the magnetic frame 8. Before the engine is used, the protective plate 9 and the magnetic frame 8 are magnetically attached. When the engine is used, the high temperature and high pressure exhaust gas in the crankcase 3 can push open the protective plate 9, so that the through holes 15 are opened to allow the exhaust gas to transfer. After the crankcase 3 cools down, the protective plate 9 and the magnetic frame 8 seal and close the through holes 15 to prevent the exhaust gas from flowing back.

[0020] In order to achieve unidirectional opening of the protective plate 9 to the grid 6, such as Figure 4 and 5 As shown, in some embodiments, the protective plate 9 can be rotatably mounted on the grid 6 with an outer plate 10 for the outer plate 10 to adhere to the surface of the grid 6 and seal the through hole 15. Furthermore, an elastic support piece 11 is provided on the side of the outer plate 10 near the grid 6 to provide rotatable elastic support between the outer plate 10 and the grid 6. Then, a magnetic layer 12 is provided on the periphery of the elastic support piece 11 to facilitate the connection between the spring support piece and the magnetic frame 8, and to provide a certain magnetic positioning for the vertical position of the protective plate 9 for sealing the through hole 15. When the exhaust gas pressure in the crankcase 3 is greater than the magnetic force between the two structures, the protective plate 9 can be pushed open to open the grid and allow the exhaust gas to enter the filter chamber 4. The elastic support piece 11 can be made of stainless steel alloy or elastic metal material, and a high-temperature resistant sealing gasket is added to the contact surface between the elastic support piece 11 and the grid 6 to improve the sealing performance. The magnetic layer 12 can be made of magnetic metal coating (such as iron, cobalt, or nickel material).

[0021] In the design of the outer plate 10, the size of the outer plate 10 is set to be larger than the size of the through hole 15. The magnetic layer 12 and the magnetic frame 8 have the same shape. The magnetic attraction strength of the magnetic frame 8 and the magnetic layer 12 is designed according to the maximum exhaust gas pressure of the crankcase under different working conditions of the motorcycle engine. This ensures that the protective plate 9 can be smoothly opened when the exhaust gas pressure is greater than the magnetic attraction strength, and that the through hole 15 can be stably sealed when not in operation. This provides favorable conditions for the one-way switching of the protective plate 9 on the grid 6.

[0022] It is worth noting that, in order to prevent fuel or oil from clogging the filter chamber 4, unburned fuel and oil in the exhaust gas can be filtered, such as... Figure 3 and 6 As shown, in some embodiments, a first filter plate 13 and a second filter plate 14 can be arranged in parallel in the filter chamber 4. The upper ends of the first filter plate 13 and the second filter plate 14 are inclined towards the grid 6. A guide plate 23 is inclinedly arranged on the side of the filter chamber 4 near the cooling pipe 5. The lower end of the guide plate 23 is inclined towards the second filter plate 14. The guide plate 23 and the first filter plate 13 and the second filter plate 14 are arranged in a V-shaped structure. In some embodiments, a hydrophobic coating can also be sprayed on the outer surface of the first filter plate 13 and the second filter plate 14 to facilitate the guidance of the incoming waste gas and sludge, prevent oil accumulation, filter the waste gas with the first filter plate 13 and the second filter plate 14, and then collect the waste gas through the guide plate 23 and collect it uniformly into the cooling pipe 5. This fully collects the unburned particles in the waste gas, reduces the waste gas resistance, and improves the waste gas delivery rate.

[0023] Secondly, such as Figure 7 and 8As shown, staggered through holes 15 are formed on both the first filter plate 13 and the second filter plate 14. Exhaust gas passes through these through holes 15 in both plates. The diameter of the through holes 15 in the first and second filter plates 13 and 14 is set to 3-5 mm, and the spacing between the holes is 8-10 mm. The through holes 15 on the two filter plates are staggered at 45°. This maximizes the contact area between the exhaust gas and the filter plates while ensuring the exhaust gas flow rate, thus improving the filtration effect on unburned fuel and oil. The different output positions facilitate increasing the contact area between the exhaust gas and the filter. The contact area of ​​the plates is then increased. A first collection plate 16 is provided on the side of the first filter plate 13 away from the grid 6, and a second collection plate 17 is also provided on the second filter plate 14. The first collection plate 16 and the second collection plate 17 are arranged on the same side and opposite to each other. The first collection plate 16 and the second collection plate 17 are both opposite to the through hole 15, which facilitates the guidance of the exhaust gas passing through the through hole 15 to the first collection plate 16 or the second collection plate 17, isolates unburned fuel and sludge in the exhaust gas, increases the cleanliness of the exhaust gas, and fully filters the exhaust gas.

[0024] To adapt to different engine operating conditions and the output of different exhaust gas temperatures in crankcase 3, furthermore, such as Figure 8 As shown, in some embodiments, the first collecting plate 16 can be configured in an L-shape. One end of the first collecting plate 16 near the first filter plate 13 is configured as a spacer 18, and the end of the spacer 18 is configured as an adjusting portion 19. Then, an inner retracting plate 20 is provided on the side of the adjusting portion 19 near the first filter plate 13. The inner retracting plate 20 is fixedly connected to the adjusting portion 19. When selecting materials, the coefficient of thermal expansion of the material used for the adjusting portion 19 is greater than that of the material used for the inner retracting plate 20. Finally, a limiting ventilation portion 21 can be provided at the edge of the inner retracting plate 20 for limiting the inner retracting plate 20 and the first filter plate 13, and a central opening is provided. The opening allows for the flow of exhaust gas while preventing excessive deformation. The material of the inner converging plate 20 is the same as that of the limiting ventilation section 21. When high-temperature exhaust gas passes through the through hole 15, part of the exhaust gas temperature is absorbed by the first collecting plate 16. By utilizing the different thermal expansion coefficients of the materials used in the adjusting section 19 and the inner converging plate 20, one side of the adjusting section 19 is more likely to deform, causing the first collecting plate 16 to open outward, increasing the opening size, and allowing for a larger exhaust gas output, thus reducing wind speed resistance. Finally, the identical structure of the first collecting plate 16 and the second collecting plate 17 facilitates the adjustment of the wind speed of the flowing exhaust gas, improving the flexibility and practicality of exhaust gas circulation.

[0025] When the exhaust gas recirculation structure is used for a long time, such as Figure 3As shown, in some embodiments, an oil drain valve 22 can be installed through the lower end of the filter chamber 4, extending the lower end of the oil drain valve 22 to the outside of the engine cylinder head 2 for the transfer of dirty oil. By opening the oil drain valve 22, it is convenient for external personnel to clean the oil in a timely manner, thereby increasing the exhaust gas flow rate. The oil drain valve 22 adopts a manual knob structure, which is convenient for operators to quickly open and drain the dirty oil. It is recommended to open the oil drain valve 22 to clean the dirty oil every 5,000 kilometers or when regularly checking the oil accumulation in the filter chamber, so as to avoid the long-term accumulation of oil and clogging of the filter plate or cooling pipe 5. The filtered exhaust gas can be placed near the intake pipe 1 through the cooling pipe 5. Furthermore, heat dissipation fins can be installed on the outside of the cooling pipe 5 to further enhance the pressure difference advantage of "the temperature of the cooling pipe is lower than the temperature of the exhaust gas in the crankcase 3", which helps the exhaust gas to transfer smoothly. The cooling pipe 5 can use heat dissipation metal materials (such as aluminum or copper alloy) to reduce the heat in the exhaust gas and allow the exhaust gas in the crankcase 3 to circulate and be discharged smoothly.

[0026] Working principle of this invention: Step 1: When the motorcycle engine is running, the intake manifold 1 delivers gas to the combustion chamber of the cylinder head 2, which assists in the combustion of fuel and drives the crankshaft to do work. Some of the exhaust gas enters the crankcase 3. To achieve exhaust gas recirculation, the exhaust gas can pass through the through holes 15 of the grid 6, push the protective plate 9, separate the magnetic layer 12 from the magnetic frame 8, and enter the filter chamber 4.

[0027] Step 2: The exhaust gas passes through the first filter plate 13 and the second filter plate 14 arranged in parallel within the filter chamber 4. It first passes through the first filter plate 13 and the second filter plate 14 through the staggered through holes 15, and then is guided in the opposite direction by the first collection plate 16 and the second collection plate 17 to filter and separate the unburned fuel and oil in the exhaust gas. The L-shaped collection plate, with the use of the interval part 18 and the limiting ventilation part 21, serves as the exhaust gas outlet. By using the different thermal expansion coefficients of the adjustment part 19 and the inner retracting plate 20, the high temperature exhaust gas can be used to deform the adjustment part 19, open the collection plate to expand the opening and reduce resistance, and adapt to different working conditions.

[0028] Step 3: The filtered exhaust gas is guided by the guide plate 23 and collected in the cooling pipe 5. The pipe body is made of heat dissipation materials such as aluminum and copper alloy, and the external heat dissipation fins are used to cool the filtered exhaust gas. At the same time, the temperature difference between the cooling pipe 5 and the crankcase 3 helps the exhaust gas transfer. The exhaust gas enters the intake pipe 1 through the PVC valve 7 made of nylon + glass fiber or metal valve body material at the top, and returns to the combustion chamber to supply fuel for combustion, realizing the recycling of exhaust gas and the re-combustion of fuel particles in the exhaust gas.

[0029] Step 4: When the engine is in use for a long time, the drain valve 22 can be rotated to clean the oil stains in the cavity and prevent blockage, so as to ensure the exhaust gas flow rate and circulation efficiency.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. The present invention is not limited to the above embodiments; the embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An engine exhaust gas recirculation structure, comprising an intake pipe (1), wherein an engine cylinder head (2) and a crankcase (3) are sequentially connected to the end of the intake pipe (1), characterized in that: The engine cylinder head (2) is provided with a filter chamber (4) that is connected to the crankcase (3). A grid (6) is provided on one side of the filter chamber (4) near the crankcase (3). A cooling pipe (5) is provided on the other side of the filter chamber (4). A PVC valve (7) is provided at the top of the cooling pipe (5) that is connected to the intake pipe (1) for direct recycling of exhaust gas in the crankcase (3).

2. The engine exhaust gas recirculation structure according to claim 1, characterized in that: The grid (6) has several through holes. A magnetic frame (8) is provided on the side of the grid (6) away from the crankcase (3). A protective plate (9) is rotatably provided at the lower end of the magnetic frame (8), and the protective plate (9) is magnetically attached to the magnetic frame (8) for the anti-reverse treatment of exhaust gas.

3. The engine exhaust gas recirculation structure according to claim 2, characterized in that: The protective plate (9) includes an outer plate (10) rotatably mounted on the grid (6). An elastic support piece (11) is provided on the side of the outer plate (10) near the grid (6). A magnetic layer (12) is provided on the periphery of the elastic support piece (11). The elastic support piece (11) is a high-temperature resistant sealing gasket, and the magnetic layer (12) is a magnetic metal coating.

4. The engine exhaust gas recirculation structure according to claim 3, characterized in that: The outer plate (10) is larger than the through hole. The magnetic layer (12) has the same shape as the magnetic frame (8). The magnetic layer (12) is used in conjunction with the magnetic frame (8).

5. The engine exhaust gas recirculation structure according to claim 1, characterized in that: The filter chamber (4) is provided with a first filter plate (13) and a second filter plate (14) arranged in parallel. The upper ends of the first filter plate (13) and the second filter plate (14) are inclined toward the grid (6). A guide plate (23) is inclined on the side of the filter chamber (4) near the cooling pipe (5). The lower end of the guide plate (23) is inclined toward the second filter plate (14) for collecting unburned particles in the exhaust gas.

6. The engine exhaust gas recirculation structure according to claim 5, characterized in that: Both the first filter plate (13) and the second filter plate (14) are provided with through holes (15). The through holes (15) on the first filter plate (13) and the second filter plate (14) are staggered. A first collection plate (16) is provided on the side of the first filter plate (13) away from the grid (6). A second collection plate (17) is provided on the second filter plate (14) on the same side as the first collection plate (16) and distributed opposite to it. Both the first collection plate (16) and the second collection plate (17) are opposite to the through holes for the purpose of fully filtering the exhaust gas.

7. The engine exhaust gas recirculation structure according to claim 6, characterized in that: The first collecting plate (16) has an L-shaped structure. The first collecting plate (16) includes a spacer (18) connected to the first filter plate (13). An adjustment part (19) is provided at the end of the spacer (18). An inwardly closing piece (20) is provided on the side of the adjustment part (19) near the first filter plate (13). The first collecting plate (16) has the same structure as the second collecting plate (17) and is used to adjust the wind speed of the circulating exhaust gas.

8. The engine exhaust gas recirculation structure according to claim 7, characterized in that: The coefficient of thermal expansion of the adjustment part (19) is greater than that of the inner retractor (20), and the edge end of the inner retractor (20) is provided with a limiting ventilation part (21).

9. The engine exhaust gas recirculation structure according to claim 1, characterized in that: The lower end of the filter chamber (4) is provided with an oil drain valve (22), which extends to the outside of the engine cylinder head (2). The cooling pipe (5) is located near the intake pipe (1). The cooling pipe (5) is made of heat dissipation metal material and is used for the circulation and discharge of exhaust gas in the crankcase (3).

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