An EGR check valve and EGR system

Abstract

This application discloses an EGR one-way valve and an EGR system. The EGR one-way valve includes a base and a valve plate. The base has an intake side and an exhaust side. The valve plate is installed on the exhaust side and includes a corrugated segment corresponding to the exhaust port position. Multiple waves of the corrugated segment are arranged along the inclined direction of the exhaust side. The angle of the collision surface where the corrugated segment collides with the exhaust gas is changed compared to related technologies. This allows the corrugated segment to partially offset the force on the valve plate, reducing the final force exerted on the valve plate by the exhaust gas. This keeps the valve plate closed under low pressure differential, ensuring that the valve plate can only open when the exhaust gas pressure exceeds a preset pressure differential. This reduces the opening frequency of the valve plate and lowers the risk of frequent valve plate breakage due to frequent opening.

Description

Technical Field

[0001] This application relates to the field of engine technology, and in particular to an EGR check valve and an EGR system. Background Technology

[0002] EGR (Exhaust Gas Recirculation) system returns a small portion of the exhaust gas produced by a diesel or gasoline engine to the cylinders, reducing NOx formation and improving the engine's emissions levels.

[0003] like Figure 1 The diagram shown is a schematic of the EGR system of the relevant technology. After the exhaust gas is discharged through the exhaust manifold 01, part of the exhaust gas passes through the EGR valve 02, the EGR cooler 03 and the EGR check valve 04 and enters the EGR cooling pipeline 05, and then enters the intake pipe 06 through the EGR cooling pipeline.

[0004] The function of EGR check valve 04 is to prevent intake air from flowing back into EGR cooler 03 and EGR valve 02 through EGR cooling pipe 05 when the intake pressure is greater than the exhaust pressure, which would cause the intake pressure to drop and the engine performance to decrease.

[0005] like Figures 2-5 The diagram shows the structure of a traditional EGR check valve. The EGR check valve has a base 041, an inlet 042, a sealing ring, a valve plate 043, and an exhaust port 044. The valve plate 043 covers the exhaust port 044. One end of the valve plate 043 near the inlet 042 is fixed by a rivet 045, and the other end of the valve plate 043 away from the inlet 042 is a free end. When the exhaust gas pressure is higher than the intake pressure, the valve plate 043 deforms, the free end of the valve plate 043 lifts up, and the valve plate 043 opens. When the exhaust gas pressure is lower than the intake pressure, the valve plate 043 does not deform and closes.

[0006] Engine exhaust is a pulse energy wave, while the intake pressure is a constant pressure. The pressure difference between the exhaust pressure and the intake pressure fluctuates, causing the valve plate to open and close frequently over a long period of time, resulting in frequent valve plate breakage. Utility Model Content

[0007] This application proposes an EGR check valve to reduce the risk of valve plate breakage. This application also proposes an EGR system.

[0008] To achieve the above objectives, this application provides an EGR check valve, including a base and a valve plate.

[0009] The base has an air intake side and two oppositely arranged exhaust sides. The exhaust sides are inclined relative to the air intake side and have exhaust ports.

[0010] The valve plate is installed on the exhaust side and is used to open or close the exhaust port. The valve plate includes a wave-shaped segment corresponding to the position of the exhaust port, and multiple waves of the wave-shaped segment are arranged along the inclined direction of the exhaust side.

[0011] Preferably, in the above-mentioned EGR one-way valve, the valve plate includes a fixed end and a free end, the fixed end being closer to the intake side relative to the free end, and the fixed end and / or the free end being a flat plate capable of fitting against the exhaust side.

[0012] Preferably, in the above-mentioned EGR check valve, the fixed end is riveted to the base.

[0013] Preferably, in the above-mentioned EGR check valve, the fixed end is hinged to the base, and a reset member is provided at the hinge position of the fixed end. The reset member is used to apply a force to the valve plate that is opposite to the opening direction of the valve plate.

[0014] Preferably, in the above-mentioned EGR check valve, the trough of the wavy section of the valve plate is higher than the plane where the exhaust side is located.

[0015] Preferably, in the above-mentioned EGR check valve, the included angles of the two sides of the multiple waves of the wavy segment of the valve plate are the same.

[0016] Preferably, in the above-mentioned EGR check valve, the included angle between the two sides of the multiple waves of the wavy segment of the valve plate gradually decreases along the gas flow direction.

[0017] Preferably, in the above-mentioned EGR check valve, the intake port on the intake side is connected to both exhaust ports on the exhaust side.

[0018] Preferably, in the above-mentioned EGR check valve, the included angle of the wave of the valve plate is 36°-144°.

[0019] An EGR system includes an EGR check valve, wherein the EGR check valve is the EGR check valve described in any of the above embodiments.

[0020] The EGR check valve provided in this application includes a base and a valve plate. The base has an intake side and an exhaust side. The valve plate is installed on the exhaust side and includes a corrugated segment corresponding to the exhaust port position. Multiple waves of the corrugated segment are arranged along the inclined direction of the exhaust side. The angle of the collision surface where the corrugated segment collides with the exhaust gas is changed compared to related technologies. This allows the corrugated segment to partially offset the force on the valve plate, reducing the final force exerted on the valve plate by the exhaust gas. This keeps the valve plate closed under low pressure differential, ensuring that the valve plate can only open when the exhaust gas pressure exceeds a preset pressure differential. This reduces the opening frequency of the valve plate and lowers the risk of frequent valve plate breakage due to frequent opening.

[0021] Embodiments of this application also disclose an EGR system, including an EGR check valve, which is the EGR check valve described in any of the above embodiments. Since the EGR check valve has the aforementioned technical effects, the EGR system with this EGR check valve also has the same technical effects, and will not be elaborated further here. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort, and this application can be applied to other similar scenarios based on the provided drawings. Unless obvious from the linguistic context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0023] Figure 1 This is the schematic diagram of the EGR system;

[0024] Figure 2 This is a schematic diagram of the existing EGR check valve.

[0025] Figure 3 This is a schematic diagram of the bottom structure of an existing EGR check valve;

[0026] Figure 4 This is a schematic diagram of the existing EGR check valve opening structure;

[0027] Figure 5 This is a side view of the existing EGR check valve when it is open;

[0028] Figure 6 This is a simulation diagram of the internal pressure of an existing EGR check valve;

[0029] Figure 7 This is a simulation diagram of the pressure distribution on the exhaust side of an existing EGR check valve;

[0030] Figure 8 This is a schematic diagram of the structure of the EGR check valve disclosed in the embodiments of this application;

[0031] Figure 9 This is a schematic diagram of the bottom structure of the EGR check valve disclosed in the embodiments of this application;

[0032] Figure 10 This is a side view of the EGR check valve disclosed in an embodiment of this application;

[0033] Figure 11 yes Figure 10 A magnified view of part A in the image.

[0034] The attached diagram is described below:

[0035] 01-Exhaust manifold; 02-EGR valve; 03-EGR cooler; 04-EGR check valve; 05-EGR aftercooler piping; 06-Intake pipe;

[0036] 041-Base; 042-Air inlet; 043-Valve plate; 044-Exhaust port; 045-Rivet;

[0037] 1-Base; 11-Air inlet; 12-Exhaust outlet;

[0038] 2-Valve plate; 21-Fixed end; 22-Free end; 23-Wave section; 24-Side A; 25-Side B. Detailed Implementation

[0039] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. The described embodiments are only a part of the embodiments of the present application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are within the scope of protection of the present application.

[0040] It should be noted that, for ease of description, only the parts relevant to the application are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features.

[0041] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0042] In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more.

[0043] like Figure 2 As shown, the base is generally triangular prism-shaped, with a first rectangular face, a second rectangular face, and a third rectangular face. The first rectangular face is the air intake side of the EGR one-way valve, with an air intake port. The second and third rectangular faces are located on both sides of the first rectangular face and are arranged opposite to each other. The second and third rectangular faces are inclined relative to the first rectangular face. The second and third rectangular faces are the exhaust side of the EGR one-way valve, with an exhaust port. The exhaust port is connected to the air intake port. A valve plate is installed on the exhaust side to open or close the exhaust port.

[0044] The end of the valve plate near the intake side is a fixed end and connected to the base, while the end of the valve plate away from the intake side is a free end and not connected to the base. When the exhaust pressure is higher than the intake pressure, the free end of the valve plate can move away from the base.

[0045] like Figure 3 and Figure 5 As shown, when the EGR check valve opens, it relies on the deformation of the valve plate, the free end of the valve plate tilts up, and a gap is generated between the valve plate and the base to form an exhaust gas discharge channel.

[0046] like Figure 7 As shown, the EGR check valve disclosed in the embodiment of this application includes a base 1 and a valve plate 2. The base 1 has an intake side and an exhaust side. Optionally, there is one intake side and two exhaust sides. The exhaust sides are located on both sides of the intake side and are inclined relative to the intake side. The exhaust side has an exhaust port 12.

[0047] Valve plate 2 is installed on the exhaust side. Valve plate 2 includes a wave-shaped segment 23 corresponding to the position of exhaust port 12. Multiple waves of the wave-shaped segment 23 are arranged along the inclined direction of the exhaust side, that is, there are at least two waves along the inclined direction of the exhaust side relative to the intake side. At least two waves are arranged side by side along the inclined direction of the exhaust side.

[0048] The EGR check valve disclosed in the embodiments of this application has a wavy section 23 designed at the position of the valve plate 2 corresponding to the exhaust port 12. The angle of the collision surface of the wavy section 23 colliding with the exhaust gas is changed compared with related technologies. It can achieve the effect of using the wave of the wavy section 23 to offset part of the force on the valve plate 2, reduce the force of the exhaust gas on the valve plate 2, keep the valve plate 2 closed under low pressure difference, and make the valve plate 2 open only when the exhaust gas pressure exceeds the preset pressure difference. This reduces the opening frequency of the valve plate 2 and reduces the risk of frequent valve plate 2 breakage due to frequent opening.

[0049] The individual waves of wave segment 23 are triangular along the cross section perpendicular to the exhaust side, such as... Figure 10 As shown, for ease of subsequent description, the surface of the wave closer to the intake side is named side A 24, and the surface of the wave farther from the intake side is named side B 25. The angle between side A 24 and side B 25 is θ. The portion between side A 24 and side B 25 is the projection of side A 24 and side B 25 onto the plane perpendicular to the exhaust side. This projection is equal to the area of ​​the portion of the valve plate 2 located between side A 24 and side B 25.

[0050] The velocity of the EGR exhaust gas near the exhaust side is very low. Therefore, the force analysis does not consider the dynamic pressure of the gas, only the static pressure. The pressure of the EGR exhaust gas acting on valve plate 2 is perpendicular to side A 24 and side B 25 of valve plate 2. The pressure F acting on side A 24... A and the pressure F acting on side B 25 B Perform a force analysis and apply the pressure F from side A at 24. A Decompose into F Ax and F AY The pressure F on side B at 25 degrees. B Decompose into F Bx and F BY F Ax With F Bx Opposite directions will cancel each other out, F AY and F BY Since waves moving in the same direction will have their forces superimposed, the force on a single wave is F. AY +F BY This offsets part of the force on valve plate 2, allowing valve plate 2 to remain closed under low pressure differential.

[0051] like Figure 9As shown, the fixed end 21 of the valve plate 2 is closer to the intake side than the free end 22. The fixed end 21 and / or the free end 22 are flat plates that can fit against the exhaust side, so that when the valve plate 2 is closed, the fixed end 21 and / or the free end 22 can fit against the exhaust side, increasing the contact area between the valve plate 2 and the exhaust side, and ensuring the seal between the valve plate 2 and the exhaust side when the valve plate 2 is closed.

[0052] In some embodiments, the valve plate 2 also includes a flat plate structure on both sides of its opening direction. Specifically, the flat plate structure of the valve plate 2 is located around the wavy section 23 of the valve plate 2. After the valve plate 2 is attached to the exhaust side, the periphery of the valve plate 2 can be attached to the exhaust side to ensure the seal between the valve plate 2 and the exhaust side.

[0053] In some embodiments, the wave-shaped segment 23 of the valve plate 2 extends from one end of the valve plate 2 in the opening direction to the other end of the valve plate 2 in the opening direction. In order to ensure the sealing between the valve plate 2 and the base 1, this application provides sealing gaskets with the same shape as the valve plate 2 on both sides of the base 1 located in the opening direction of the valve plate 2, so as to ensure the sealing between the circumference of the valve plate 2 and the exhaust side when the valve plate 2 is closed.

[0054] Optionally, the gasket is mounted on the valve plate 2, and a sealing groove is formed on the base 1 to mate with the gasket; or, the gasket is mounted on the base 1, and the valve plate 2 fits against the gasket when the exhaust port is closed.

[0055] In some embodiments, the fixed end 21 of the valve plate 2 is riveted to the base 1 to achieve a fixed connection between the fixed end 21 of the valve plate 2 and the base 1.

[0056] The rivet presses the fixed end 21 of the valve plate 2 onto the base 1. The free end 22 of the valve plate 2 is pushed to deform under the pressure difference between the exhaust gas pressure and the intake gas pressure. The opening power of the valve plate 2 of the EGR check valve disclosed in this application is the difference between the pressure difference and the restoring force of the valve plate 2. That is, the opening of the valve plate 2 needs to overcome the restoring force of the valve plate 2. The EGR check valve disclosed in this application solves the problem of frequent opening of the valve plate 2 under low pressure difference by combining riveting and the corrugated section 23.

[0057] In some embodiments, the fixed end 21 of the valve plate 2 is hinged to the base 1. Specifically, the fixed end 21 of the valve plate 2 is provided with a hinge shaft, the base 1 is provided with a bushing, and the valve plate 2 is hinged to the bushing through the hinge shaft. When the exhaust gas pressure is greater than the intake gas pressure, the valve plate 2 opens.

[0058] A reset element is provided at the hinge shaft position of the fixed end 21. The reset element applies a force to the valve plate 2 in the opposite direction to the opening direction of the valve plate 2. The greater the opening angle of the valve plate 2, the greater the force applied to the valve plate 2 by the reset element. Optionally, the reset element is a torsion spring.

[0059] like Figure 9As shown, the trough of the wavy section 23 of the valve plate 2 is higher than the plane where the exhaust side is located. The wavy section 23 of the valve plate 2 is located outside the exhaust port 12. The wavy section 23 of the valve plate 2 and the exhaust side form a space to accommodate exhaust gas, creating a larger exhaust space for exhaust gas. At the same time, the area where the wavy section 23 of the valve plate 2 is set is larger, and more waves on the wavy section 23 can offset and disperse the pressure.

[0060] The exhaust gas fills the space between the wavy section and the plane of the exhaust side. The gas in this space is in a stable pressure state, and this space forms a pressure stabilizing chamber. When the gas entering the EGR one-way valve flows along the exhaust side, it collides with the gas in the above space. On the one hand, this reduces the friction between the EGR exhaust gas and the exhaust side, and on the other hand, it buffers the collision between the EGR exhaust gas and the valve plate, reducing the force of the EGR exhaust gas on the valve plate 2. This helps to solve the problem of frequent opening of the valve plate 2 under low pressure difference.

[0061] In some embodiments, the included angles of the two sides of the multiple waves of the wavy segment 23 of the valve plate 2 are the same, and in this embodiment, the two sides are symmetrically distributed with respect to the wave crests. The valve plate in this embodiment has a simple structure and is easy to manufacture.

[0062] In some embodiments, along the gas flow direction, the included angle between the two sides of the multiple waves of the corrugated segment 23 of the valve plate 2 gradually decreases. As the exhaust gas pressure gradually increases along the gas flow direction, this embodiment adjusts the included angle between the two sides of the waves of the corrugated segment 23 according to the change in exhaust gas pressure to enhance the wave's pressure-reducing ability, further reducing the likelihood of the valve plate 2 remaining closed under low pressure differentials, reducing the opening frequency of the valve plate 2, and lowering the risk of the valve plate 2 breaking due to frequent opening.

[0063] An air intake port 11 is provided on the intake side. In some embodiments, the air intake port 11 on the intake side is connected to the exhaust ports 12 on both exhaust sides to improve the pressure uniformity through each exhaust port 12, reduce the exhaust resistance at each part, and improve the EGR rate of the engine.

[0064] The pressure at the exhaust port 12 of the EGR check valve is uneven. Due to the resistance of the valve body wall of the EGR check valve, the pressure in the central area between the two exhaust sides is higher, which is the high-pressure area, while the area closer to the exhaust side is the low-pressure area.

[0065] Although this application changes the shape of the valve plate 2 corresponding to the position of the exhaust port 12, the projected area of ​​the valve plate 2 along the plane perpendicular to the exhaust side remains unchanged. The force analysis is as follows: Figure 10 As shown, the projected area of ​​the wave along the plane perpendicular to the exhaust side is S0, and the area of ​​side A24 is S. A The area of ​​side B, 25° is S. B , with S A=S B Taking S1 as an example for analysis,

[0066] According to the Pythagorean theorem,

[0067] Such as simulation Figure 6 As shown, the pressure in the middle of the EGR check valve is high, and the gas pressure decreases closer to the exhaust side. The mainstream gas is in the middle, as... Figure 7 The diagram shows the pressure distribution on the exhaust side. It can be seen that the gas pressure gradually increases from the intake side. The gas pressure is related to the position of the EGR check valve's outlet plane. Correspondingly, the gas pressure intensity is also related to the position of the EGR check valve's outlet plane. The pressure P0 on the conventional plane is related to the pressure 24P on side A. A And side B 25P B The sum of their pressures is the same, that is, P0 = P A +P B P A =P B =P1, P0 = 2P1;

[0068] The pressure F0 on the conventional plane, and the pressure F on side A24 A The pressure F on side B at 25 degrees. B F A =F B =F1;

[0069]

[0070] ∵

[0071] ∴

[0072] Assumption Let k be the coefficient, i.e., F0 = kF1;

[0073] Since 0° < θ < 180°, therefore That is, 0 < k < 4.

[0074] To reduce the risk of activation, F0 > F1, and correspondingly, 1 < k < 4;

[0075] Since 1 < k < 4

[0076] ∴

[0077] ∵

[0078] Therefore, 29° < θ < 180°

[0079] With a safety factor of 1.2, we get 36° < θ < 144°.

[0080] Embodiments of this application also disclose an EGR system, including an EGR check valve, wherein the EGR check valve is the EGR check valve described in any of the above embodiments.

[0081] Since the EGR check valve has the above-mentioned technical effects, the EGR system with the EGR check valve also has the same technical effects, which will not be elaborated here.

[0082] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed, and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. The scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described application concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An EGR check valve, characterized in that, Includes a base (1) and a valve plate (2), The base (1) has an air intake side and two oppositely arranged exhaust sides. The exhaust sides are inclined relative to the air intake side, and an exhaust port (12) is provided on the exhaust side. The valve plate (2) is installed on the exhaust side for opening or closing the exhaust port (12). The valve plate (2) includes a wave-shaped segment (23) corresponding to the position of the exhaust port (12). Multiple waves of the wave-shaped segment (23) are arranged along the inclined direction of the exhaust side.

2. The EGR check valve according to claim 1, characterized in that, The valve plate (2) includes a fixed end (21) and a free end (22). The fixed end (21) is closer to the intake side than the free end (22). The fixed end (21) and / or the free end (22) are flat plates that can fit against the exhaust side.

3. The EGR check valve according to claim 2, characterized in that, The fixed end (21) is riveted to the base (1).

4. The EGR check valve according to claim 2, characterized in that, The fixed end (21) is hinged to the base (1), and a reset member is provided at the hinge position of the fixed end (21). The reset member is used to apply a force to the valve plate (2) opposite to the opening direction of the valve plate (2).

5. The EGR check valve according to claim 1, characterized in that, The trough of the wavy section (23) of the valve plate (2) is higher than the plane on which the exhaust side is located.

6. The EGR check valve according to claim 1, characterized in that, The included angles of the two sides of the multiple waves of the wave-shaped segment (23) of the valve plate (2) are the same.

7. The EGR check valve according to claim 1, characterized in that, Along the direction of gas flow, the included angle between the two sides of the multiple waves of the wavy segment (23) of the valve plate (2) gradually decreases.

8. The EGR check valve according to claim 1, characterized in that, The air inlet (11) on the intake side is connected to the two exhaust outlets (12) on the exhaust side.

9. The EGR check valve according to claim 1, characterized in that, The included angle of the wave of the valve plate (2) is 36°-144°.

10. An EGR system, characterized in that, Includes an EGR check valve, wherein the EGR check valve is the EGR check valve according to any one of claims 1-9.

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