A new noise reduction exhaust system for an in-line four-cylinder engine

Abstract

The utility model discloses a novel noise reduction exhaust system of in-line four cylinder engine belongs to engine exhaust technical field, solves the problem of big exhaust noise of existing in-line four cylinder engine. It includes with the first cylinder exhaust passage, second cylinder exhaust passage, third cylinder exhaust passage, fourth cylinder exhaust passage of in-line four cylinder engine's four combustion chamber - corresponding connection first cylinder exhaust manifold, second cylinder exhaust manifold one end common connection has first exhaust branch pipe, third cylinder exhaust manifold, fourth cylinder exhaust manifold one end common connection has second exhaust branch pipe, first exhaust branch pipe, second exhaust branch pipe one end common connection has the exhaust pipe, first cylinder exhaust manifold with the exhaust pipe between, second cylinder exhaust manifold with the exhaust pipe between all is equipped with the shunt passage of the both intercommunication. The utility model's exhaust system effectively reduces the main gas flow noise of exhaust, prolongs the service life of engine.

Description

Technical Field

[0001] This utility model relates to the field of engine exhaust technology, and more specifically, it relates to a novel noise reduction exhaust system for an inline four-cylinder engine. Background Technology

[0002] Engine noise is the loud sound produced by an engine during operation, transmitted directly into space from the engine block and its main components. Engine noise varies depending on the engine type, speed, load, and operating conditions. Aerodynamic noise is the noise generated by gas disturbance and the interaction between gas and other objects. In engines, it includes intake noise, exhaust noise, and fan noise.

[0003] Exhaust noise primarily originates at the start of exhaust, when exhaust gases are expelled in pulses from the exhaust valve gaps and rapidly enter the atmosphere from the exhaust port, creating high-energy, complex noise with components including the fundamental frequency and its higher harmonics. This noise is the most significant and energetic noise source in automobiles and engines, often exceeding the overall engine noise by 10-15 dB(A). Besides the fundamental frequency noise and its higher harmonics, exhaust noise also includes air column resonance noise in the exhaust manifold and exhaust main, vortex noise on the valve stem back, and turbulence noise on the inner walls of the exhaust system pipes. Furthermore, exhaust noise also includes exhaust gas injection and impact noise.

[0004] The louder the engine exhaust noise, the more likely it is to cause noise pollution, affecting the driving experience, and also causing damage to engine parts. Therefore, how to further reduce engine exhaust noise has become a key technology in engine development. Utility Model Content

[0005] The technical problem to be solved by this utility model is to address the above-mentioned shortcomings of the prior art. The purpose of this utility model is to provide a new noise reduction exhaust system for an inline four-cylinder engine, which reduces the main airflow noise of the exhaust and extends the service life of the engine.

[0006] To achieve the above objectives, this utility model provides a novel noise-reducing exhaust system for an inline four-cylinder engine, comprising a first cylinder exhaust passage, a second cylinder exhaust passage, a third cylinder exhaust passage, and a fourth cylinder exhaust passage, each corresponding to one of the four combustion chambers of the inline four-cylinder engine. The first cylinder exhaust passage, the second cylinder exhaust passage, the third cylinder exhaust passage, and the fourth cylinder exhaust passage are respectively connected to a first cylinder exhaust manifold, a second cylinder exhaust manifold, a third cylinder exhaust manifold, and a fourth cylinder exhaust manifold. One end of the first cylinder exhaust manifold and the second cylinder exhaust manifold are connected to a first exhaust branch pipe, and one end of the third cylinder exhaust manifold and the fourth cylinder exhaust manifold are connected to a second exhaust branch pipe. One end of the first exhaust branch pipe and the second exhaust branch pipe are connected to an exhaust pipe. A diversion channel connecting the first cylinder exhaust manifold and the exhaust pipe, and between the second cylinder exhaust manifold and the exhaust pipe, are provided.

[0007] As a further improvement, the exhaust system also includes a turbocharger, an exhaust aftertreatment system, and a muffler connected in sequence, with the exhaust pipe connected to the front end of the turbocharger's turbine housing and the rear end of the turbocharger's turbine housing connected to the exhaust aftertreatment system.

[0008] Furthermore, the exhaust pipe is arranged laterally on the inline four-cylinder engine, and the turbocharger is located in the middle of the exhaust pipe.

[0009] Furthermore, the exhaust pipe is connected to the first exhaust branch pipe and the second exhaust branch pipe, as well as to the first exhaust branch pipe and the first cylinder exhaust manifold and the second cylinder exhaust manifold, and the second exhaust branch pipe and the third cylinder exhaust manifold and the fourth cylinder exhaust manifold, all via flanges.

[0010] Furthermore, the exhaust pipe, the first cylinder exhaust manifold, the second cylinder exhaust manifold, the third cylinder exhaust manifold, the fourth cylinder exhaust manifold, the first exhaust branch pipe, and the second exhaust branch pipe are all double-layered clamped pipes.

[0011] Beneficial effects

[0012] Compared with the prior art, the advantages of this utility model are as follows:

[0013] This utility model's inline four-cylinder engine employs a one-to-one intake method with four exhaust ports and exhaust manifolds corresponding to the four combustion chambers. The exhaust manifolds corresponding to the first two cylinders merge into the first exhaust branch pipe, and the exhaust manifolds corresponding to the last two cylinders merge into the second exhaust branch pipe, forming two exhaust streams. These two exhaust streams then converge at the exhaust pipe for discharge. Furthermore, the flow is diverted through the diversion channels corresponding to the first two cylinders, allowing 15%-30% of the main exhaust airflow from the first two cylinders to be diverted and directly converge at the exhaust pipe. This method significantly reduces exhaust noise because the diversion disrupts the flow of the main airflow, appropriately reducing its velocity and impact noise. Simultaneously, it creates partial resonance with the main airflow. Resonance utilizes the principles of sound wave reflection and interference to alter the propagation characteristics of sound waves, hindering the outward propagation of sound energy. Certain frequencies of sound waves from the diverted airflow cancel each other out due to their opposite phase, thus achieving noise reduction. This exhaust method also improves the uniformity of exhaust from each cylinder, preventing uneven exhaust pressure. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the main structure of this utility model;

[0015] Figure 2 This is the airflow direction diagram of this utility model.

[0016] Wherein: 1-Inline four-cylinder engine, 2-Exhaust port of cylinder 1, 3-Exhaust port of cylinder 2, 4-Exhaust port of cylinder 3, 5-Exhaust port of cylinder 4, 6-Exhaust manifold of cylinder 1, 7-Exhaust manifold of cylinder 2, 8-Exhaust manifold of cylinder 3, 9-Exhaust manifold of cylinder 4, 10-Exhaust branch pipe of cylinder 1, 11-Exhaust branch pipe of cylinder 2, 12-Exhaust pipe, 13-Split channel, 14-Turbocharger, 15-Exhaust aftertreatment system, 16-Muffler, 17-Cylinder head. Detailed Implementation

[0017] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0018] See Figure 1-2As shown, a novel noise-reducing exhaust system for an inline four-cylinder engine includes a first cylinder exhaust manifold 2, a second cylinder exhaust manifold 3, a third cylinder exhaust manifold 4, and a fourth cylinder exhaust manifold 5, each corresponding to one of the four combustion chambers of the inline four-cylinder engine 1. The first cylinder exhaust manifold 14, the second cylinder exhaust manifold 15, the third cylinder exhaust manifold 16, and the fourth cylinder exhaust manifold 17 are all independently located within the cylinder head 33, enabling independent exhaust from the four manifolds. The first cylinder exhaust manifold 2, the second cylinder exhaust manifold 3, the third cylinder exhaust manifold 4, and the fourth cylinder exhaust manifold 5 are respectively connected to the first cylinder exhaust manifold 6 and the second cylinder exhaust manifold 6. Manifold 7, exhaust manifold 8 of the third cylinder, exhaust manifold 9 of the fourth cylinder, exhaust manifold 6 of the first cylinder, and exhaust manifold 7 of the second cylinder are all connected to a first exhaust branch pipe 10. One end of exhaust manifold 8 of the third cylinder and exhaust manifold 9 of the fourth cylinder are all connected to a second exhaust branch pipe 11. One end of exhaust branch pipe 10 and exhaust branch pipe 11 are all connected to an exhaust pipe 12. A diversion channel 13 is provided between exhaust manifold 6 of the first cylinder and exhaust pipe 12, and between exhaust manifold 7 of the second cylinder and exhaust pipe 12, so as to directly divert part of the exhaust airflow to exhaust pipe 12.

[0019] This utility model's inline four-cylinder engine employs a one-to-one intake method with four exhaust ports and exhaust manifolds corresponding to the four combustion chambers. The exhaust manifolds corresponding to the first two cylinders merge into the first exhaust branch pipe, and the exhaust manifolds corresponding to the last two cylinders merge into the second exhaust branch pipe, forming two exhaust streams. These two exhaust streams then converge at the exhaust pipe for discharge. Furthermore, the flow is diverted through the diversion channels corresponding to the first two cylinders, allowing 15%-30% of the main exhaust airflow from the first two cylinders to be diverted and directly converge at the exhaust pipe. This method significantly reduces exhaust noise because the diversion disrupts the flow of the main airflow, appropriately reducing its velocity and impact noise. Simultaneously, it creates partial resonance with the main airflow. Resonance utilizes the principles of sound wave reflection and interference to alter the propagation characteristics of sound waves, hindering the outward propagation of sound energy. Certain frequencies of sound waves from the diverted airflow cancel each other out due to their opposite phase, thus achieving noise reduction. This exhaust method also improves the uniformity of exhaust from each cylinder, preventing uneven exhaust pressure.

[0020] Preferably, the exhaust system further includes a turbocharger 14, an exhaust aftertreatment system 15, and a muffler 16 connected in sequence. The exhaust pipe 12 is connected to the front end of the turbine chamber of the turbocharger 14 to drive the turbocharger 2 to rotate. The rear end of the turbine chamber of the turbocharger 14 is connected to the exhaust aftertreatment system 15 to purify the exhaust gas and meet the requirements of environmental protection emissions. The exhaust gas is then further reduced in noise by the muffler 29.

[0021] Preferably, the exhaust pipe 12 is arranged laterally on the inline four-cylinder engine 1, wherein the turbocharger 14 is located in the middle of the exhaust pipe 12, thereby optimizing the layout of the engine exhaust system.

[0022] Preferably, the exhaust pipe 12 is connected to the first exhaust branch pipe 10 and the second exhaust branch pipe 11, the first exhaust branch pipe 10 is connected to the first cylinder exhaust manifold 6 and the second cylinder exhaust manifold 7, and the second exhaust branch pipe 11 is connected to the third cylinder exhaust manifold 8 and the fourth cylinder exhaust manifold 9 via flanges, so as to achieve detachable connection and facilitate disassembly and maintenance.

[0023] Preferably, exhaust pipe 12, first cylinder exhaust manifold 6, second cylinder exhaust manifold 7, third cylinder exhaust manifold 8, fourth cylinder exhaust manifold 9, first exhaust branch pipe 10, and second exhaust branch pipe 11 are all double-layered sandwich pipes, which serve as heat insulation. Depending on the application, heat insulation material can be injected into the sandwich of the double-layered sandwich pipe to further improve the heat insulation performance. For example, in marine engines, cooling water can be introduced into the sandwich; in automotive engines, heat insulation cotton can be filled into the sandwich.

[0024] The above are merely preferred embodiments of this utility model. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model, and these will not affect the implementation effect of this utility model or the practicality of the patent.

Claims

1. A novel noise-reducing exhaust system for an inline four-cylinder engine, comprising a first cylinder exhaust manifold (2), a second cylinder exhaust manifold (3), a third cylinder exhaust manifold (4), and a fourth cylinder exhaust manifold (5) connected one-to-one with the four combustion chambers of the inline four-cylinder engine (1), characterized in that, The exhaust passages of the first cylinder (2), the second cylinder (3), the third cylinder (4), and the fourth cylinder (5) are respectively connected to the exhaust manifolds of the first cylinder (6), the second cylinder (7), the third cylinder (8), and the fourth cylinder (9). One end of the exhaust manifolds of the first cylinder (6) and the second cylinder (7) are connected to the first exhaust branch pipe (10). One end of the exhaust manifolds of the third cylinder (8) and the fourth cylinder (9) are connected to the second exhaust branch pipe (11). One end of the exhaust branch pipe (10) and the second exhaust branch pipe (11) are connected to the exhaust pipe (12). A diversion channel (13) connecting the first cylinder exhaust manifold (6) and the exhaust pipe (12) and the second cylinder exhaust manifold (7) and the exhaust pipe (12) is provided.

2. The novel noise-reducing exhaust system for an inline four-cylinder engine according to claim 1, characterized in that, The exhaust system also includes a turbocharger (14), an exhaust aftertreatment system (15) and a muffler (16) connected in sequence. The exhaust pipe (12) is connected to the front end of the turbine chamber of the turbocharger (14), and the rear end of the turbine chamber of the turbocharger (14) is connected to the exhaust aftertreatment system (15).

3. A novel noise-reducing exhaust system for an inline four-cylinder engine according to claim 2, characterized in that, The exhaust pipe (12) is arranged laterally on the inline four-cylinder engine (1), and the turbocharger (14) is located in the middle of the exhaust pipe (12).

4. A novel noise-reducing exhaust system for an inline four-cylinder engine according to claim 1, characterized in that, The exhaust pipe (12) is connected to the first exhaust branch pipe (10) and the second exhaust branch pipe (11) by flanges, as are the first exhaust branch pipe (10) and the first cylinder exhaust manifold (6) and the second cylinder exhaust manifold (7), and the second exhaust branch pipe (11) and the third cylinder exhaust manifold (8) and the fourth cylinder exhaust manifold (9).

5. A novel noise-reducing exhaust system for an inline four-cylinder engine according to any one of claims 1-4, characterized in that, The exhaust pipe (12), the first cylinder exhaust manifold (6), the second cylinder exhaust manifold (7), the third cylinder exhaust manifold (8), the fourth cylinder exhaust manifold (9), the first exhaust branch pipe (10), and the second exhaust branch pipe (11) are all double-layered cavity pipes.

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