A gas inlet connection pipe and an engine

Abstract

This invention provides an air-injection connection pipe and an engine. The air-injection connection pipe includes a connecting pipe body and an air-injection pipe body. The connecting pipe body has a first conical cavity and a second conical cavity on the same axis. The small-diameter end of the first conical cavity is connected to the small-diameter end of the second conical cavity, and the large-diameter end of the first conical cavity is connected to a first air inlet. The large-diameter end of the second conical cavity is connected to a first air outlet. One end of the air-injection pipe body extends into the second conical cavity, and the second air outlet of the air-injection pipe body is located inside the second conical cavity and close to its axis. By designing the first and second conical cavities as a converging and expanding structure similar to a Laval nozzle, a stable low-pressure zone is formed inside the second conical cavity. Combined with the air-injection pipe body extending into the second conical cavity, this provides negative pressure suction, allowing air to be drawn into the second conical cavity through the air-injection pipe body without additional power. This provides sufficient and uniform oxygen for the secondary reaction of the three-way catalytic converter, significantly reducing CO emissions.

Description

Technical Field

[0001] This utility model relates to the field of engine technology, specifically to an air supply connection pipe and an engine. Background Technology

[0002] Engines emit various harmful gases during operation, including CO, nitrogen oxides (NOx), and hydrocarbons (HC). Direct emissions can seriously harm the ecological environment and human health. Currently, the industry commonly uses mufflers with catalysts (three-way catalytic converters) to treat exhaust gases. The catalyst promotes secondary chemical reactions (secondary combustion) of harmful gases, oxidizing CO into harmless CO2, oxidizing HC into H2O and CO2, and reducing NOx into N2.

[0003] However, the oxidation of CO by a three-way catalytic converter depends on sufficient oxygen. If the oxygen content in the exhaust gas is insufficient, CO oxidation will be incomplete, leading to a significant decrease in purification efficiency. Existing air injection solutions have many drawbacks, such as the air injection location being off-center from the core exhaust gas flow area, resulting in uneven mixing of oxygen and exhaust gas and low utilization. Furthermore, some air injection devices require modifications to the existing engine structure, resulting in poor compatibility and increased modification costs and assembly difficulty. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of this utility model is to provide an air supply connection pipe and an engine to solve or at least alleviate one or more of the above-mentioned technical problems or other problems existing in the prior art.

[0005] To achieve the above objectives, this utility model provides an air replenishment connecting pipe, including a connecting pipe body with a first air inlet and a first air outlet. The connecting pipe body has a first conical cavity and a second conical cavity on the same axis. The small-diameter end of the first conical cavity is connected to the small-diameter end of the second conical cavity, the large-diameter end of the first conical cavity is connected to the first air inlet, and the large-diameter end of the second conical cavity is connected to the first air outlet. An air replenishment pipe body is also provided on the connecting pipe body. One end of the air replenishment pipe body extends into the second conical cavity. The air replenishment pipe body has a second air inlet and a second air outlet. The second air outlet is located within the second conical cavity and is close to the axis of the second conical cavity.

[0006] Preferably, the distance between the second air outlet and the small diameter end of the second conical cavity is denoted as L1, and the distance between the second air outlet and the large diameter end of the second conical cavity is denoted as L2, wherein L1 is less than L2.

[0007] Preferably, the axis of the air supply tube is perpendicular to the axis of the second conical cavity.

[0008] Preferably, the connection between the first conical cavity and the second conical cavity is a rounded transition.

[0009] Preferably, the connecting tube body has a transition cavity, the inner wall of the transition cavity is cylindrical, one end of the transition cavity is connected to the large diameter end of the first conical cavity, and the first air inlet is located at the other end of the transition cavity.

[0010] Preferably, the end of the air supply pipe away from the second air outlet is bent to form an extension pipe, and the second air inlet is provided on the extension pipe.

[0011] Preferably, a first flange is provided on the outer wall of the connecting pipe near the first air inlet, and a second flange is provided on the outer wall of the connecting pipe near the first air outlet.

[0012] This utility model also provides an engine, including the above-mentioned air supply connection pipe.

[0013] The beneficial effects of this utility model are:

[0014] This utility model discloses an air inlet connection pipe and engine. By designing the first and second conical cavities into a contraction and expansion structure similar to a Laval nozzle, a stable low-pressure zone is formed in the second conical cavity. In conjunction with the air inlet pipe body extending into the second conical cavity, a negative pressure suction force is provided to the air inlet pipe body. Air can be drawn into the second conical cavity through the air inlet pipe body without additional power, providing sufficient and uniform oxygen for the secondary reaction of the three-way catalytic converter and significantly reducing CO emissions.

[0015] Meanwhile, the axial region of the second conical cavity is the core area with the highest exhaust gas velocity. Because the second exhaust port is close to the axis of the second conical cavity, the supplemented oxygen can be directly entrained and dispersed by the high-speed exhaust gas, thereby improving the mixing uniformity. In addition, the connecting pipe only connects to the cylinder head and muffler through the first intake port and the first exhaust port at both ends, without modifying the original engine structure. Existing models can be directly replaced, thereby reducing modification costs and assembly threshold. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0017] Figure 1 This is a cross-sectional schematic diagram of the air supply connection pipe provided in one embodiment of the present utility model;

[0018] Figure 2 This is a schematic diagram of the gas supply connection pipe;

[0019] Figure label:

[0020] 10. Connecting pipe body; 11. First air inlet; 12. First air outlet; 13. First conical cavity; 14. Second conical cavity; 15. Transition cavity; 20. Air supply pipe body; 21. Second air inlet; 22. Second air outlet; 30. Extension pipe body; 40. First flange; 50. Second flange. Detailed Implementation

[0021] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0022] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

[0023] 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", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 utility model.

[0024] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly defined.

[0025] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0026] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] like Figure 1 and Figure 2 As shown, in one embodiment of this utility model, a gas replenishment connecting pipe is provided, including a connecting pipe body 10 and a gas replenishment pipe body 20. The connecting pipe body 10 has a first air inlet 11 and a first air outlet 12 at its two ends. The connecting pipe body 10 has a first conical cavity 13 and a second conical cavity 14 coaxially aligned. The small-diameter end of the first conical cavity 13 communicates with the small-diameter end of the second conical cavity 14, and the large-diameter end of the first conical cavity 13 communicates with the first air inlet 11. The large-diameter end of the second conical cavity 14 communicates with the first air outlet 12. The gas replenishment pipe body 20 is fixedly installed on the connecting pipe body 10. One end of the gas replenishment pipe body 20 extends into the second conical cavity 14. The gas replenishment pipe body 20 has a second air inlet 21 and a second air outlet 22. The second air outlet 22 is located within the second conical cavity 14 and close to its axis.

[0028] This air supply connection pipe is designed based on the Laval nozzle principle and Bernoulli's principle. The first conical cavity 13 is a contraction cavity, and the second conical cavity 14 is an expansion cavity. After the exhaust gas enters the first conical cavity 13 through the first air inlet 11, it flows towards the smaller diameter end of the first conical cavity 13, where the exhaust gas velocity gradually increases and the pressure decreases. After entering the second conical cavity 14, the exhaust gas velocity further increases (supersonic flow can be achieved if it reaches the speed of sound). A stable low-pressure zone is formed inside the second conical cavity 14, thereby providing negative pressure suction for the air supply pipe body 20, which draws air into the second conical cavity 14 through the air supply pipe body 20.

[0029] This embodiment discloses an air supply connection pipe, which designs the first conical cavity 13 and the second conical cavity 14 into a constriction and expansion structure similar to a Laval nozzle. A stable low-pressure zone is formed in the second conical cavity 14. Together with the air supply pipe body extending into the second conical cavity 14, it provides negative pressure suction to the air supply pipe body 20. Air can be drawn into the second conical cavity 14 through the air supply pipe body 20 without additional power, providing sufficient and uniform oxygen for the secondary reaction of the three-way catalytic converter and significantly reducing CO emissions.

[0030] Meanwhile, the axial region of the second conical cavity 14 is the core region with the highest exhaust gas velocity. Since the second exhaust port 22 is close to the axis of the second conical cavity 14, the supplemented oxygen can be directly entrained and dispersed by the high-speed exhaust gas, thereby improving the mixing uniformity. In addition, the connecting pipe 10 only connects to the cylinder head and muffler through the first intake port 11 and the first exhaust port 12 at both ends, without modifying the original structure of the engine. Existing models can be directly replaced, thereby reducing the modification cost and assembly threshold.

[0031] In one embodiment, the distance between the second air outlet 22 and the small-diameter end of the second conical cavity 14 is denoted as L1, and the distance between the second air outlet 22 and the large-diameter end of the second conical cavity 14 is denoted as L2, where L1 is less than L2. Since the pressure inside the second conical cavity 14 gradually increases from the small-diameter end to the large-diameter end, the area near the small-diameter end of the second conical cavity 14 is the area with the lowest pressure and strongest negative pressure. Therefore, by designing the second air outlet 22 in this area, the suction negative pressure of the air supply tube 20 can be maximized, ensuring that sufficient air can be drawn in and improving the air supply effect.

[0032] In addition, the oxygen ejected from the second exhaust port 22 will flow to the first exhaust port 12 along with the exhaust gas. During this process, the high-speed exhaust gas will continue to mix with oxygen. Therefore, this structural design can provide a sufficient path for the mixing of exhaust gas and oxygen, thereby further improving the mixing uniformity.

[0033] In one embodiment, the axis of the supplementary air pipe 20 is perpendicular to the axis of the second conical cavity 14. This structural design allows oxygen to directly enter the high-speed flow field of the exhaust gas after being ejected from the second exhaust port 22, which reduces the obstruction to the flow of the exhaust gas and achieves efficient mixing of the exhaust gas and oxygen.

[0034] In one embodiment, the connection between the first conical cavity 13 and the second conical cavity 14 is rounded. This rounded transition design allows the exhaust gas to flow along a smooth curved surface, ensuring a stable increase in exhaust gas velocity to maintain a low-pressure environment within the second conical cavity 14. Simultaneously, during operation, the connecting pipe 10 is subjected to high-temperature exhaust gas and pressure impacts. The connection between the first conical cavity 13 and the second conical cavity 14 is a stress concentration area, and the rounded transition disperses this stress, enhancing the high-temperature and high-pressure resistance of the connection, thereby extending the service life of the connecting pipe 10.

[0035] In one embodiment, the connecting pipe 10 has a transition cavity 15, which is cylindrical. One end of the transition cavity 15 is connected to the large-diameter end of the first conical cavity 13, and the first air inlet 11 is located at the other end of the transition cavity 15. If the exhaust gas discharged from the cylinder head directly enters the first conical cavity 13, it may cause uneven distribution of exhaust gas velocity within the first conical cavity 13, affecting the low-pressure stability of the second conical cavity 14. By adding the cylindrical transition cavity 15, the exhaust gas discharged from the cylinder head can be buffered, allowing the exhaust gas to fully diffuse and stabilize within the transition cavity 15, forming a uniform airflow before entering the first conical cavity 13.

[0036] In one embodiment, the end of the air supply pipe 20 away from the second air outlet 22 is bent to form an extension pipe 30, and the second air inlet 21 is provided on the extension pipe 30. Depending on the actual space of the machine model, the position and orientation of the second air inlet 21 can be adjusted to ensure that the second air inlet 21 is always in an area with sufficient air, avoiding air intake obstruction. In this embodiment, the second air inlet 21 is connected to the air guide shroud (not shown in the attached diagram), so that a portion of the airflow drawn into the air guide shroud can enter the connecting pipe 10 through the air supply pipe 20 to achieve air replenishment.

[0037] In one embodiment, the connection between the air supply pipe 20 and the extension pipe 30 is rounded. This rounded transition at the connection allows the airflow to flow along a smooth curved surface, avoiding the generation of eddies and ensuring smooth airflow from the extension pipe 30 to the air supply pipe 20, thereby maintaining a stable air supply volume.

[0038] In one embodiment, a first flange 40 is provided on the outer wall of the connecting pipe body 10 near the first air inlet 11, and a second flange 50 is provided on the outer wall of the connecting pipe body 10 near the first air outlet 12. The first flange 40 is mated with the cylinder head exhaust flange, and the second flange 50 is mated with the catalytic converter flange and fastened with bolts. The first flange 40 and the second flange 50 can be manufactured according to the dimensions of existing models without changing the existing equipment interface structure, thereby ensuring the universality of the air injection connection pipe, enabling direct replacement of existing models, reducing modification costs and assembly threshold.

[0039] This embodiment also provides an engine including the aforementioned air supply connection pipe. Because it uses the aforementioned air supply connection pipe, it has the same working principle and technical effects as the air supply connection pipe in the above embodiments, and will not be described again here.

[0040] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. An air-supplementing connection pipe characterized by comprising: The application relates to a gas supplementing connecting pipe. The connecting pipe body (10) is provided with a first air inlet hole (11) and a first air outlet hole (12), the first connecting pipe body (10) is internally provided with coaxial first and second conical cavities (13) and (14), the small-diameter end of the first conical cavity (13) is communicated with the small-diameter end of the second conical cavity (14), the large-diameter end of the first conical cavity (13) is communicated with the first air inlet hole (11), and the large-diameter end of the second conical cavity (14) is communicated with the first air outlet hole (12); and The gas supplementing pipe body (20) is arranged on the connecting pipe body (10), one end of the gas supplementing pipe body (20) extends into the second conical cavity (14), the gas supplementing pipe body (20) is provided with a second air inlet hole (21) and a second air outlet hole (22), and the second air outlet hole (22) is arranged in the second conical cavity (14) and is close to the axis of the second conical cavity (14).

2. The air supplement connection pipe according to claim 1, wherein The distance between the second air outlet hole (22) and the small-diameter end of the second conical cavity (14) is denoted as L1, the distance between the second air outlet hole (22) and the large-diameter end of the second conical cavity (14) is denoted as L2, and the L1 is smaller than the L2.

3. The air supplement connection pipe according to claim 2, characterized by The axis of the gas supplementing pipe body (20) is perpendicular to the axis of the second conical cavity (14).

4. The air supplement connection pipe according to claim 1, wherein The first conical cavity (13) and the second conical cavity (14) are connected through a circular arc transition.

5. The air supplement connection pipe according to claim 1, wherein The connecting pipe body (10) is internally provided with a transition cavity (15), the inner wall of the transition cavity (15) is in a cylindrical shape, one end of the transition cavity (15) is communicated with the large-diameter end of the first conical cavity (13), and the first air inlet hole (11) is arranged at the other end of the transition cavity (15).

6. The air supplement connection pipe according to claim 1, wherein The end of the gas supplementing pipe body (20) away from the second air outlet hole (22) is bent to form an extending pipe body (30), and the second air inlet hole (21) is arranged on the extending pipe body (30).

7. The air supplement connection pipe according to claim 1, wherein The connecting pipe body (10) is provided with a first flange plate (40) on the outer wall of the pipe opening close to the first air inlet hole (11), and is provided with a second flange plate (50) on the outer wall of the pipe opening close to the first air outlet hole (12).

8. An engine characterized by, The application further relates to a gas supplementing connecting pipe comprising any one of the connecting pipes in claims 1 to 7.

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