One-way valve, EGR system and engine

Abstract

The one-way valve comprises a one-way valve body, the one-way valve body comprises at least one valve body part, the valve body part is provided with an airflow channel used for being communicated with a controlled pipeline, one end of the airflow channel is an airflow inlet, and the other end of the airflow channel is an airflow outlet; the airflow outlet is provided with at least two one-way valve plates, each one-way valve plate is rotationally matched on the valve body part, the free end of each one-way valve plate is connected with the valve body part through a reset piece, and the at least two one-way valve plates are arranged in different pressure areas of the airflow outlet; and the opening resistance of the one-way valve plate corresponding to the area with high air outlet pressure is greater than that of the one-way valve plate corresponding to the area with low air outlet pressure. The larger opening degree of the one-way valve can be set according to requirements, the exhaust resistance of EGR waste gas is reduced, the opening angles of the valve plates of the one-way valves in different gas pressure areas can be equal, and it is guaranteed that the exhaust pressure of the EGR waste gas is balanced.

Description

Technical Field

[0001] The present application relates to the technical field of engines, and more specifically, to a one-way valve, an EGR system, and an engine. Background Art

[0002] In order to reduce the generation of NO X and improve the original exhaust level of the engine, the engine usually configures an EGR (Exhaust Gas Re-circulation) system. The EGR system will re-introduce a part of the exhaust gas of the engine back into the cylinder and mix it with the fresh intake air of the engine to improve the working efficiency of the engine, improve the combustion environment, reduce the engine load, reduce the emission of NOx, reduce knocking, and extend the service life of each component.

[0003] In order to prevent the engine from experiencing intake backflow into the EGR system under the condition that the intake pressure is greater than the exhaust pressure, a one-way valve is generally added after the EGR cooler of the EGR system. The one-way valve can prevent the engine intake from flowing back into the EGR cooler, the EGR valve, etc. through the pipeline under the condition that the intake pressure is greater than the exhaust pressure, resulting in a decrease in the intake pressure and a decline in the engine performance.

[0004] The one-way valve of the EGR system includes a valve disc. When the exhaust gas pressure is higher than the intake pressure, the valve disc is in an open state, and when the exhaust gas pressure is lower than the intake pressure, the valve disc is in a closed state. In the prior art, one end of the valve disc is fixed to the valve body of the one-way valve through fixing parts such as rivets. The opening and closing of the traditional one-way valve are based on the pressure difference before and after the one-way valve. When the pressure in front of the one-way valve is large, the free end side of the valve disc will deform and spring up. The height of the spring-up is related not only to the magnitude of the pressure difference but also to the elastic deformation ability of the valve disc material itself, that is, the opening degree of the one-way valve is inversely proportional to the stiffness of the valve disc material. The stiffness of the valve disc material is also proportional to the service life of the valve disc. Therefore, in order to ensure the service life of the valve disc, the valve disc usually needs to have a certain stiffness, which affects the deformation amount of the valve disc, makes the opening angle of the valve disc not too large, resulting in a large resistance to the outlet of the EGR exhaust gas and difficulty in increasing the EGR rate of the engine.

[0005] Therefore, how to increase the opening degree of the one-way valve without affecting the service life is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present application is to provide a one-way valve to increase the opening degree of the one-way valve without affecting the service life; Another purpose of the present application is to provide an EGR system and an engine having the above one-way valve.

[0007] To achieve the above purpose, the present application provides the following technical solutions: The first aspect of the present application provides a check valve for sealing and communicating with a controlled pipeline, including a check valve body, the check valve body includes at least one valve body part, the valve body part is provided with an air flow channel for communicating with the controlled pipeline, one end of the air flow channel is an air flow inlet, and the other end is an air flow outlet; At least two check valve flaps are arranged at the air flow outlet, each check valve flap is rotatably fitted on the valve body part, and the free end of each check valve flap is connected to the valve body part through a reset member. At least two check valve flaps are arranged in different pressure regions at the air flow outlet, and the opening resistance of the check valve flap corresponding to the region with a larger outlet pressure is greater than the opening resistance of the check valve flap corresponding to the region with a smaller outlet pressure.

[0008] In a possible implementation manner, two check valve flaps are arranged at each air flow outlet, and are respectively a first valve flap and a second valve flap, and the rotation centers of the first valve flap and the second valve flap are coaxially arranged.

[0009] In a possible implementation manner, a first hinge shaft is arranged at the hinged end of the first valve flap, a second hinge shaft is arranged at the hinged end of the second valve flap, the first hinge shaft and the second hinge shaft are nested and rotatably supported on a support part on the valve body part.

[0010] In a possible implementation manner, one of the first hinge shaft and the second hinge shaft is a central shaft, and the other is a pipe shaft, and the pipe shaft is sleeved outside the central shaft; The support part is provided with a central hole for cooperating with the central shaft and an annular hole for cooperating with the pipe shaft.

[0011] In a possible implementation manner, the length of the central shaft is W1a, the length of the pipe shaft is W2a, and W1a ≤ W2a.

[0012] In a possible implementation manner, the length of the first hinge shaft is W1a, the dimension of the first valve flap in the axial direction of the first hinge shaft is W1, then (W1a - W1) / W1 = 0.3 - 0.4; And / or, The length of the second hinge shaft is W2a, the dimension of the second valve flap in the axial direction of the second hinge shaft is W2, then (W2a - W2) / W2 = 0.3 - 0.4.

[0013] In a possible implementation manner, the first hinge shaft is the central shaft and the second hinge shaft is the pipe shaft; The tube axis has an avoidance opening in the circumferential direction to avoid the first valve plate, and the avoidance opening extends from one end of the tube axis to the other end, and the central angle of the annular hole is greater than the central angle of the tube axis.

[0014] In a possible implementation, the central angle of the annular hole is less than 360°.

[0015] In a possible implementation, the rotation centers of the first valve plate and the second valve plate are located in the middle area of the air flow outlet.

[0016] In a possible implementation, the first valve plate is closer to the middle area in the air flow direction than the second valve plate; The covering area of the first valve plate is greater than the covering area of the second valve plate, and / or, the weight of the first valve plate is greater than the weight of the second valve plate.

[0017] In a possible implementation, the thickness of the first valve plate is A, the thickness of the second valve plate is B, the dimension of the first valve plate in the arrangement direction of the first valve plate and the second valve plate is L1, and the dimension of the second valve plate in the arrangement direction of the first valve plate and the second valve plate is L2; Then B = (0.8 - 0.9)A, L2 = (0.3 - 0.4)L1.

[0018] In a possible implementation, there are multiple valve body parts arranged in the first direction, and the air flow inlets of each valve body part are connected or separated.

[0019] In a possible implementation, air flow outlets are arranged on both sides of the valve body part in the second direction, the first direction is perpendicular to the second direction, and the air flow outlets on both sides of the valve body part are communicated with the air flow inlet of the valve body part.

[0020] In a possible implementation, the air flow direction at the air flow inlet forms an obtuse angle with the air flow direction at the air flow outlet.

[0021] In a possible implementation, the resetting member is a door closer, a valve plate connection part is arranged on the one-way valve plate, a valve body connection part is arranged on the valve body part, one end of the door closer is connected to the valve plate connection part, and the other end is connected to the valve body connection part.

[0022] In a possible implementation, the thickness of the one-way valve plate is 0.9 mm - 3 mm.

[0023] The check valve provided by the present application rotatably fits the check valve disc on the valve body portion, and a reset member is connected between the free end of the check valve disc and the valve body portion to maintain the closed state of the check valve disc. When the pressure difference before and after the check valve disc can push the check valve disc to overcome the reset force of the reset member, the check valve disc will be pushed to swing to open the air flow channel, so that the air flow can flow in a specific direction in the controlled pipeline through the air flow channel. When the pressure difference before and after the check valve disc cannot overcome the reset force of the reset member, the check valve disc will be pulled back by the reset force to close the air flow channel and prevent the air flow from flowing in the opposite direction of the specific direction.

[0024] The present application does not need to fix the check valve disc by rivets, so the stress concentration caused by the rivets on the check valve disc is eliminated, and the problem of the check valve disc breaking during repeated opening is avoided. The present application changes the structure that the traditional check valve must rely on the elastic deformation of the check valve disc itself to open. The present application does not rely on the deformation of the check valve disc to achieve opening and closing. Therefore, the thickness of the check valve disc can be increased according to requirements to ensure that the check valve disc has greater stiffness, and then the service life of the check valve disc can be guaranteed. Moreover, since the opening of the check valve is not controlled by the elastic deformation of the check valve disc, a larger opening of the check valve can be set according to requirements, reducing the outlet resistance of the EGR exhaust gas. The frictional resistance generated by the rotation of the check valve disc is much smaller than the energy loss generated by the deformation of the check valve disc, which is also beneficial to reducing the EGR exhaust gas resistance and increasing the EGR rate of the engine.

[0025] The present application provides at least two check valve discs for each air flow outlet. Compared with a single check valve disc, at the same opening angle, the opening area of the present application is larger, which is beneficial to reducing the EGR exhaust gas resistance and increasing the EGR rate ability of the engine. In addition, at least two check valve discs are arranged in different pressure regions of the air flow outlet, and the opening resistance of the check valve disc corresponding to the region with a larger outlet pressure is greater than the opening resistance of the check valve disc corresponding to the region with a smaller outlet pressure, so that the opening angles of the check valve discs in different gas pressure regions can be made equivalent, ensuring the balance of the EGR exhaust gas outlet pressure.

[0026] A reset member is connected to each check valve disc of the present application, and the reset force of the reset member can ensure that the leaked gas of the EGR valve does not flow into the intake side, meeting the engine emission requirements and avoiding the problem of the check valve disc repeatedly opening and closing and hitting the valve body portion.

[0027] The second aspect of the present application provides an EGR system, including an EGR pipeline, one end of the EGR pipeline is an exhaust side connection end, and the other end is an intake side connection end; In the direction from the exhaust side connection end to the intake side connection end, at least an EGR valve and the check valve described in any one of the above are connected in series on the EGR pipeline.

[0028] Since the EGR system provided by the present application has the above check valve, it has all the technical effects of the above check valve, which will not be elaborated herein.

[0029] The third aspect of the present application provides an engine including the EGR system as described above.

[0030] Since the engine provided by the present application has the above EGR system, it has all the technical effects of the above EGR system, which will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 Schematic structural view of a check valve in the prior art at a certain angle; Figure 2 Schematic structural view of a check valve in the prior art at another angle; Figure 3 Schematic structural view of a check valve in the prior art when in the closed state; Figure 4 Front view of a check valve in the prior art when in the open state; Figure 5 Schematic structural view of the check valve disclosed in the embodiment of the present application when in the closed state; Figure 6 Schematic structural view of the exhaust gas side of the check valve disclosed in the embodiment of the present application; Figure 7 Schematic structural view of the check valve disclosed in the embodiment of the present application when in the open state; Figure 8 Front view of the check valve disclosed in the embodiment of the present application; Figure 9 Simulation diagram of the pressure distribution of the fluid in the pipeline disclosed in the embodiment of the present application; Figure 10 Simulation diagram of the pressure distribution of the fluid in the check valve disclosed in the embodiment of the present application; Figure 11 Schematic structural view of the first valve plate disclosed in the embodiment of the present application; Figure 12 Front view of the first valve plate disclosed in the embodiment of the present application; Figure 13Schematic diagram of the structure of the second valve plate disclosed in the embodiment of the present application; Figure 14 Front view of the second valve plate disclosed in the embodiment of the present application; Figure 15 Partial enlarged view of the support part disclosed in the embodiment of the present application; Figure 16 Partial enlarged view of the hinge shaft installed on the support part disclosed in the embodiment of the present application; Figure 17 Partial enlarged view of the check valve plate in the closed state disclosed in the embodiment of the present application; Figure 18 Partial enlarged view of the check valve plate in the open state disclosed in the embodiment of the present application; Figure 19 Cross-sectional view of the check valve disclosed in the embodiment of the present application; Figure 20 Comparison diagram of the opening area of the check valve plate disclosed in the embodiment of the present application; Figure 21 Schematic diagram of the gas path of the engine disclosed in the embodiment of the present application.

[0033] The meanings of the various reference numerals in the figure are as follows: 1 - valve body; 2 - gas flow outlet; 3 - valve plate; 4 - rivet; 5 - seal; 6 - gas flow inlet; 7 - exhaust gas outlet; 01 - engine body; 02 - EGR valve; 03 - check valve; 04 - EGR cooler; 100 - check valve body; 101 - gas flow inlet; 102 - gas flow outlet; 110 - valve body part; 200 - first valve plate; 201 - first valve plate connection part; 202 - first hinge shaft; 300 - support part; 301 - isolation body; 302 - central hole; 303 - annular hole; 400 - second valve plate; 401 - second valve plate connection part; 402 - second hinge shaft; 4021 - avoidance opening; 500 - seal; 600 - reset part. Detailed implementation manners

[0034] The embodiment of the present application discloses a check valve to increase the opening degree of the check valve without affecting the service life; The embodiment of the present application also discloses an EGR system and an engine having the above check valve.

[0035] Hereinafter, embodiments will be described with reference to the accompanying drawings. In addition, the embodiments shown below do not limit the application content described in the claims in any way. Further, all the contents of the configurations shown in the following embodiments are not limited to those necessary for the solution of the application described in the claims. It should be noted that, for ease of description, only the parts related to the relevant application are shown in the drawings. Without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0036] As Figure 1 and Figure 2 shown, currently, the check valve for the EGR system generally includes a valve body 1 and a valve disc 3, and a seal 5 is provided on the valve body 1. An air flow passage is provided on the valve body 1. One end of the air flow passage is an air flow inlet 6, and the other end is an air flow outlet 2. The air flow inlet 6 is communicated with the exhaust side of the engine, and the air flow outlet 2 is communicated with the intake side of the engine.

[0037] One end of the valve disc 3 is fixed to the valve body 1 by a rivet 4, and the valve disc 3 has a certain elasticity, so that the valve disc 3 can open and close the air flow passage. Usually, the valve disc 3 covers one side of the air flow outlet 2. When the exhaust gas pressure is higher than the intake pressure, the valve disc is in the open state, as Figure 1 shown. When the exhaust gas pressure (the pressure on the exhaust side of the engine, that is, the pressure at the air flow inlet 6) is lower than the intake pressure (the pressure on the intake side of the engine, that is, the pressure at the air flow outlet 2), the valve disc 3 is in the closed state, as Figure 3 shown.

[0038] As Figure 4 shown, the opening degree of the check valve is inversely proportional to the stiffness of the valve disc 3. The larger the opening degree is, the larger the exhaust gas outlet 7 formed between the valve disc 3 and the valve body 1 is. And the stiffness of the valve disc 3 material is proportional to the service life of the valve disc 3. Therefore, in order to ensure the service life of the valve disc 3, usually the valve disc 3 needs to have a certain stiffness, which will inevitably affect the opening angle of the valve disc 3, resulting in a large resistance to the EGR exhaust gas and great difficulty in increasing the EGR rate of the engine.

[0039] Through research on the traditional check valve, the inventor found that the valve disc 3 of the traditional check valve has a high reliability risk and is easy to break. The engine exhaust is a pulsed energy wave, while the intake pressure is a steady pressure, and the pressure difference between the two is fluctuating. At the same time, since the leakage amount of the EGR valve cannot reach zero leakage, the pressure difference before and after the valve disc 3 of the check valve is a continuous fluctuating energy, and this fluctuating pressure difference will cause the valve disc 3 of the check valve to open and close very frequently for a long time.

[0040] One end of the valve disc 3 is fixed to the valve body 1 by a rivet 4, belonging to a cantilever beam structure. When it needs to be opened, the valve disc 3 deforms, and the free end far from the fixed end will tilt up, so as to increase the gap between the valve disc 3 and the valve body 1 and ensure the gas outflow. In order to achieve deformation, the valve disc cannot increase its stiffness by increasing its thickness. As described above, due to the frequent opening and closing of the valve disc 3 of the check valve, the valve disc 3 will frequently touch the valve body 1, and the low stiffness of the valve disc 3 will cause frequent fracture problems of the valve disc 3.

[0041] The inventor also found that when the engine demand EGR rate is 0, but the leakage of the EGR valve cannot reach 0 leakage, so there is a risk of EGR exhaust gas leaking into the intake system. Since the check valve can only prevent the intake air from flowing back, even under a very small pressure difference condition, it cannot prevent the leaked EGR exhaust gas from flowing out, which will cause the problem of high engine emissions. And this problem will increase with the increase of the engine operation time. The gap of the EGR valve will become larger and larger, and the valve disc 3 of the check valve will also deform with the increase of the operation time, further increasing the emission risk.

[0042] In view of this, the embodiment of the present application discloses a check valve to overcome the above defects found by the inventor through research.

[0043] As Figures 5 - 7 shown, the check valve disclosed in the embodiment of the present application is used to be hermetically connected to the controlled pipeline to realize the one-way conduction of the controlled pipeline, that is, it can only conduct in a specific direction and is in a cut-off state in the opposite direction of the specific direction. The check valve can be applied to the EGR system, that is, as the check valve of the EGR system, the controlled pipeline is the EGR pipeline of the EGR system. It should be noted that the check valve disclosed in this embodiment can also be applied to other fields and is not limited to the specific field of the EGR system. For the convenience of understanding, the following will take the application of this check valve to the EGR system as an example for introduction.

[0044] The check valve disclosed in this embodiment includes a check valve body 100. The check valve body 100 is the main supporting component of the check valve and is used to provide an installation basis for components such as the check valve disc. A corresponding seal 500 can be arranged on the outer side of the check valve body 100 for sealing cooperation with the installation position of the check valve. In this embodiment, a valve body frame can be arranged on the outer side of the check valve body 100, and the seal 500 can be arranged on the valve body frame to improve the sealing effect. When the check valve is installed at the installation position of the EGR system, the seal 500 is in sealing cooperation with the inner wall of the installation position.

[0045] The one-way valve body 100 includes at least one valve body part 110. The valve body part 110 is provided with an air flow channel for communicating with the pipeline to be controlled. One end of the air flow channel is an air flow inlet 101, and the other end is an air flow outlet 102. The air flow inlet 101 is used to communicate with the exhaust side of the engine, and the air flow outlet 102 is used to communicate with the intake side of the engine.

[0046] The air flow outlet 102 is provided with at least two one-way valve flaps, and each one-way valve flap is rotatably fitted on the valve body part 110. In this embodiment, by rotatably fitting the one-way valve flap with the valve body part 110, the air flow outlet 102 can be opened and closed. During the rotation of the one-way valve flap along its rotation center, the relative position relationship with the air flow outlet 102 can be changed. When all the one-way valve flaps block the air flow outlet 102, the one-way valve is in the closed state to prevent the fluid from flowing reversely along the pipeline to be controlled; when the one-way valve flap leaves the air flow outlet 102, the one-way valve is in the open state, and the fluid can pass through the one-way valve through the air flow channel and maintain the one-way conduction state of the pipeline to be controlled.

[0047] The free end of each one-way valve flap is connected to the valve body part 110 through a reset member 600, that is, one end of the reset member 600 is connected to the free end of the one-way valve flap, and the other end is connected to the valve body part 110. Under the elastic force of the reset member 600, a pulling force can be generated on the free end of the one-way valve flap to make the one-way valve flap close the air flow outlet 102 and keep the one-way valve in the closed state.

[0048] The number of one-way valve flaps corresponding to each air flow outlet 102 can be two or more than two. In this embodiment, the specific number of one-way valve flaps is not limited, as long as the air flow outlet 102 can be completely closed. Those skilled in the art can select the number of one-way valve flaps corresponding to each air flow outlet 102 according to actual needs.

[0049] As Figure 9 shown, according to gas dynamics, when gas moves in a pipeline, the gas along the pipe wall will be affected by the frictional resistance of the pipe wall and the frictional force between gases. Therefore, the pressure distribution of the gas in the pipeline shows a trend of decreasing radially from the center to the periphery, that is, the central area of the pipeline is the high-pressure area, and the pipe wall area is the low-pressure area (red is the high-pressure area, blue and green are the low-pressure areas), and the pressure distribution is as Figure 5 shown.

[0050] The pressure distribution of the gas in the one-way valve is as Figure 10 shown. The pressure at the air flow inlet 101 is relatively uniform, but the pressure at the air flow outlet 102 is uneven. The upper area of the air flow outlet 102 is the high-pressure area, and the lower area is the low-pressure area.

[0051] The inventor has found through research that if the opening resistance of each check valve flap at the air outlet 102 is the same, the opening angle of the check valve flap corresponding to the high-pressure area of the air outlet 102 will be large, while the opening angle of the check valve flap corresponding to the low-pressure area of the air outlet 102 will be small. This will result in uneven air output at the air outlet 102.

[0052] As Figure 19 shown, based on this, in this embodiment, at least two check valve flaps are arranged in different pressure areas of the air outlet 102. And the opening resistance of the check valve flap corresponding to the area with a large outlet pressure is greater than the opening resistance of the check valve flap corresponding to the area with a small outlet pressure. It should be noted that the area with a large outlet pressure (the area corresponding to the rectangular dotted line frame) and the area with a small outlet pressure (the area corresponding to the elliptical dotted line frame) are in a relative pressure magnitude relationship, that is, when comparing the two, one has a greater pressure than the other. Taking two check valve flaps as an example, for the sake of easy understanding, the two check valve flaps are respectively defined as the first flap 200 and the second flap 400.

[0053] If the outlet pressure of the area where the first flap 200 is set is greater than the outlet pressure of the area where the second flap 400 is set, then the opening resistance of the first flap 200 needs to be designed to be greater than that of the second flap 400. Thus, a check valve flap with a large opening resistance is correspondingly set in the area with a large pressure, and a check valve flap with a small opening resistance is correspondingly set in the area with a small pressure. The high-pressure gas in the high-pressure area generates a greater opening thrust on the check valve flap, and the low-pressure gas in the low-pressure area generates a smaller opening thrust on the check valve flap; combined with the fact that the check valve flap in the high-pressure area has a large opening resistance, while the check valve flap in the low-pressure area has a small opening resistance, the opening angles of the check valve flaps in different gas pressure areas can be made equivalent, achieving the purpose of pressure balance at the air outlet 102.

[0054] The check valve disclosed in the embodiment of the present application rotatably fits the check valve flap on the valve body part 110, and a reset member 600 is connected between the free end of the check valve flap and the valve body part 110 to keep the check valve flap in a closed state. When the pressure difference before and after the check valve flap can push the check valve flap to overcome the reset force of the reset member 600, the check valve flap will be pushed to swing to open the air flow channel, so that the air flow can flow in a specific direction in the controlled pipeline through the air flow channel. When the pressure difference before and after the check valve flap cannot overcome the reset force of the reset member 600, the check valve flap will be pulled back by the reset force to close the air flow channel and prevent the air flow from flowing in the opposite direction of the specific direction.

[0055] The present application does not need to fix the one-way valve disc by rivets, thus eliminating the stress concentration of the one-way valve disc caused by rivets, and avoiding the problem of the one-way valve disc breaking during repeated opening. The present application changes the structure that the traditional one-way valve must rely on the elastic deformation of the one-way valve disc itself to open. The present application does not rely on the deformation of the one-way valve disc to achieve opening and closing, so the thickness of the one-way valve disc can be increased according to demand (the thickness of the one-way valve disc can be designed to be 0.9mm-3mm, that is, the thickness of the one-way valve disc in this embodiment can be designed to be 3-6 times the thickness of the traditional one-way valve disc), ensuring that the one-way valve disc has greater rigidity, and then the service life of the one-way valve disc can be guaranteed, and the one-way valve disc does not rely on the elastic deformation of the one-way valve disc to control the opening of the one-way valve, so a larger one-way valve opening can be set according to demand, reducing the outlet resistance of the EGR exhaust gas. The friction resistance generated by the rotation of the one-way valve disc is much smaller than the energy loss caused by the deformation of the one-way valve disc, which is also conducive to reducing the EGR exhaust gas resistance and improving the engine EGR rate.

[0056] like Figure 20 As shown, the present application sets at least two one-way valve plates (such as Figure 20 b), compared with a single one-way valve disc (such as Figure 20 a), under the same opening angle, the opening area of ​​the present application is larger (opening area b1+b2>opening area a), which is conducive to reducing the EGR exhaust gas resistance and improving the engine EGR rate capacity. In addition, at least two one-way valve discs are arranged in different pressure areas of the air flow outlet, and the opening resistance of the one-way valve disc corresponding to the area with high outlet pressure is greater than the opening resistance of the one-way valve disc corresponding to the area with low outlet pressure, so that the opening angles of the one-way valve discs in different gas pressure areas can be equal, ensuring the balance of the EGR exhaust gas outlet pressure.

[0057] Each one-way valve disc of the present application is connected to a reset member 600, and the reset force of the reset member 600 can ensure that the EGR valve leakage gas does not flow into the intake side, meeting the engine emission requirements while avoiding the problem of the one-way valve disc slapping the valve body 110 due to repeated opening and closing of the one-way valve disc.

[0058] In a specific embodiment of the present application, each air flow outlet 102 is provided with two one-way valve discs, namely a first valve disc 200 and a second valve disc 400, and the rotation centers of the first valve disc 200 and the second valve disc 400 are coaxially arranged. The rotation centers of the first valve disc 200 and the second valve disc 400 can be coaxial by nesting each other. In this way, the limiting ends of the first valve disc 200 and the second valve disc 400 can be located at the same position, and the free ends are respectively located at the two ends of the air flow outlet 102.

[0059] Of course, the rotation centers of the first valve plate 200 and the second valve plate 400 can also be located at two ends of the air flow outlet 102 respectively, so that the free ends of the first valve plate 200 and the second valve plate 400 are located at positions where the first valve plate 200 and the second valve plate 400 are close to each other. In this embodiment, the arrangement positions of the rotation centers of the first valve plate 200 and the second valve plate 400 are not limited.

[0060] As Figure 11 and Figure 13 shown, a first hinge shaft 202 is provided at the hinged end of the first valve plate 200, and a second hinge shaft 402 is provided at the hinged end of the second valve plate 400. The first hinge shaft 202 and the second hinge shaft 402 are nested and rotatably supported on a support portion 300 on the valve body portion 110. It should be noted that, in order to avoid air leakage after the first valve plate 200 and the second valve plate 400 are installed on the air flow outlet 102 of the valve body portion 110 and the air flow outlet 102 cannot be completely closed. The first hinge shaft 202 should be provided at the end of the first valve plate 200, and the second hinge shaft 402 should be provided at the end of the second valve plate 400. When the first hinge shaft 202 and the second hinge shaft 402 are coaxially nested, it can be ensured that the distance between the first valve plate 200 and the second valve plate 400 is close enough, and the small gap between the first valve plate 200 and the second valve plate 400 can also be closed by the first hinge shaft 202 and the second hinge shaft 402. It should be noted that, in order to ensure sealing, a seal should be provided between the first hinge shaft 202 and the second hinge shaft 402 and the valve body portion 110. Of course, seals should also be provided between the first valve plate 200 and the valve body portion 110, and between the second valve plate 400 and the valve body portion 110.

[0061] As Figure 15 and Figure 16 shown, in a specific embodiment of the present application, one of the first hinge shaft 202 and the second hinge shaft 402 is a central shaft, and the other is a tube shaft, and the tube shaft is sleeved outside the central shaft. That is, the central shaft is an inner shaft, which can be a solid shaft, and the tube shaft is an outer shaft, which can be a hollow shaft.

[0062] The support portion 300 is provided with a central hole 302 that cooperates with the central shaft, and an annular hole 303 that cooperates with the tube shaft. The annular hole 303 is provided outside the central hole 302. Those skilled in the art can set the diameters of the central hole 302 and the annular hole 303 according to requirements.

[0063] For the convenience of understanding, taking the first hinge shaft 202 as the central shaft and the second hinge shaft 402 as the tube shaft as an example, as Figure 13As shown, the tube body axis has an avoidance opening 4021 in the circumferential direction to avoid the first valve plate 200, and the avoidance opening 4021 extends from one end of the tube body axis to the other end. The central angle of the annular hole 303 is larger than the central angle of the tube body axis, so that the tube body axis can rotate within the annular hole 303. The radian size of the annular hole 303 needs to ensure that the second valve plate 400 has a sufficient opening range, that is, the difference between the central angle of the annular hole 303 and the central angle of the tube body axis needs to be not less than the opening angle of the second valve plate 400, otherwise the opening angle of the second valve plate 400 will be affected. In this embodiment, the first hinge shaft 202 and the second hinge shaft 402 are supported on the same support portion 300, which is more likely to ensure gas tightness.

[0064] As Figure 15 shown, the central angle of the annular hole 303 is less than 360°, that is, there is a solid part between the two ends of the annular hole 303, so that the separator 301 between the annular hole 303 and the central hole 302 can be connected through the solid part between the two ends of the annular hole 303, so as to realize the opening of the annular hole 303 and the central hole 302 on the support portion 300.

[0065] A partition can be provided at the position corresponding to the tube body axis of the air flow outlet 102, and the tube body axis is sealed with the partition through a seal to prevent air flow from leaking through the position of the tube body axis. Of course, the air flow outlet 102 may not be provided with a partition, then it is necessary to set through the position of the tube body axis to prevent gas from leaking through the avoidance opening 4021. For example, when the first valve plate 200 and the second valve plate 400 are in the closed state, the side wall of the avoidance opening 4021 close to one side wall in the air flow channel is in sealing abutment with the first valve plate 200 (the sealing method can be arbitrary, for example, a sealing strip is provided on the side wall of the avoidance opening 4021), so as to prevent gas from entering the tube body axis through the avoidance opening 4021 and leaking through the lumen of the tube body axis. When the first valve plate 200 and the second valve plate 400 are in the open state, the leakage problem does not need to be concerned about.

[0066] As Figure 12 and Figure 14 shown, the length of the central axis is W1a, and the length of the tube body axis is W2a, W1a ≤ W2a. That is, when the tube body axis is sleeved outside the central axis, the central axis can be hidden inside the tube body axis, which has a protective effect on the central axis and prevents particulate matter from entering the gap between the central axis and the central hole 302 and affecting the smooth rotation of the central axis.

[0067] It should be noted that a protective cover (not shown in the figure) can also be provided on the support portion 300 to protect the tube body axis and the central axis through the protective cover. In addition to protecting the central axis, the protective cover can also protect the tube body axis. Prevent particulate matter from entering the gap between the tube body axis and the annular hole 303 and affecting the smooth rotation of the tube body axis.

[0068] The first valve plate 200 and the first hinge shaft 202 can be designed as an integral structure, and the second valve plate 400 and the second hinge shaft 402 can also be designed as an integral structure. In this case, it is necessary to connect the support parts 300 to both ends of the first hinge shaft 202 and the second hinge shaft 402 first. Then fix the two support parts 300 on the valve body part 110. For example, the two support parts 300 can be welded or fixed to the valve body part 110 by fasteners. Of course, one side of the support part 300 and the valve body part 110 can be designed as an integral structure, and the other side of the support part 300 and the valve body part 110 can be designed as a detachable structure to facilitate the installation of the first hinge shaft 202 and the second hinge shaft 402. The first valve plate 200 and the second valve plate 400 can both be metal plates, or the first valve plate 200 and the second valve plate 400 can also be structural parts made of other materials, not limited to metal.

[0069] As Figure 12 shown, the length of the first hinge shaft 202 is W1a, and the dimension of the first valve plate 200 along the axial direction of the first hinge shaft 202 is W1. Then, (W1a - W1) / W1 = 0.3 - 0.4. With this setting, the length of the first hinge shaft 202 can be greater than the length of the first valve plate 200, so that both ends of the first hinge shaft 202 can extend beyond the first valve plate 200. Through experimental verification, setting the ratio of (W1a - W1) / W1 between 0.3 and 0.4 can avoid the problem that the first hinge shaft 202 bends over time due to its long length. It can also avoid the problem that the support length of the first hinge shaft 202 is insufficient due to its short length, resulting in the support part 300 being unable to effectively support the first hinge shaft 202.

[0070] As Figure 14 shown, the length of the second hinge shaft 402 is W2a, and the dimension of the second valve plate 400 along the axial direction of the second hinge shaft 402 is W2. Then, (W2a - W2) / W2 = 0.3 - 0.4. With this setting, the length of the second hinge shaft 402 can be greater than the length of the second valve plate 400, so that both ends of the second hinge shaft 402 can extend beyond the second valve plate 400. Through experimental verification, setting the ratio of (W2a - W2) / W2 between 0.3 and 0.4 can avoid the problem that the second hinge shaft 402 bends over time due to its long length. It can also avoid the problem that the support length of the second hinge shaft 402 is insufficient due to its short length, resulting in the support part 300 being unable to effectively support the second hinge shaft 402.

[0071] In a specific embodiment of the present application, the rotation centers of the first valve plate 200 and the second valve plate 400 are located in the middle region of the air flow outlet 102. It should be noted that the middle region of the air flow outlet 102 does not refer to the exact center position of the air flow outlet 102, but a certain range of regions. For example, the air flow outlet 102 can be evenly divided into three regions along the arrangement direction of the first valve plate 200 and the second valve plate 400, and the rotation centers of the first valve plate 200 and the second valve plate 400 are arranged in the middle region, and in the middle region, they can be arranged at any position.

[0072] Further, as Figure 19 shown, the first valve plate 200 is closer to the middle region of the air flow direction than the second valve plate 400. Those skilled in the art can understand that the middle region of the air flow direction is a high-pressure region, and the edge region of the air flow direction is a low-pressure region. Therefore, the pressure in the region where the first valve plate 200 is located is higher than the pressure in the region where the second valve plate 400 is located.

[0073] In this embodiment, the covering area of the first valve plate 200 is greater than the covering area of the second valve plate 400 and / or the weight of the first valve plate 200 is greater than the weight of the second valve plate 400. In this embodiment, through the area size relationship between the first valve plate 200 and the second valve plate 400, the opening resistance of the first valve plate 200 can be designed to be greater than the opening resistance of the second valve plate 400; or through the weight size relationship between the first valve plate 200 and the second valve plate 400, the opening resistance of the first valve plate 200 can be designed to be greater than the opening resistance of the second valve plate 400.

[0074] Thus, the region with a large pressure is correspondingly provided with the first valve plate 200 with a large opening resistance, and the region with a small pressure is correspondingly provided with the second valve plate 400 with a small opening resistance. The high-pressure gas in the high-pressure region generates a large opening thrust on the first valve plate 200, and the low-pressure gas in the low-pressure region generates a small opening thrust on the second valve plate 400; combined with the fact that the first valve plate 200 in the high-pressure region has a large opening resistance, while the second valve plate 400 in the low-pressure region has a small opening resistance, so the opening angles of the first valve plate 200 and the second valve plate 400 in different gas pressure regions can be made equivalent, achieving the purpose of pressure balance at the air flow outlet 102.

[0075] In a specific embodiment of the present application, the thickness of the first valve plate 200 is A, the thickness of the second valve plate 400 is B, the dimension of the first valve plate 200 along the arrangement direction of the first valve plate 200 and the second valve plate 400 is L1, and the dimension of the second valve plate 400 along the arrangement direction of the first valve plate 200 and the second valve plate 400 is L2.

[0076] Then B = (0.8 - 0.9)A, and L2 = (0.3 - 0.4)L1. That is, in this embodiment, by the thickness size relationship and the width size relationship between the first valve plate 200 and the second valve plate 400, the weights and covering areas of the first valve plate 200 and the second valve plate 400 are changed, and then the opening resistance of the first valve plate 200 and the second valve plate 400 is changed.

[0077] As Figure 7 shown, there can be multiple valve body parts 110 arranged along the first direction. Figure 7 In the illustrated solution, there are two valve body parts 110 in total. Of course, the number of valve body parts 110 can also exceed two, such as three, four, etc. Of course, only one can also be provided. The specific number of the valve body parts 110 is not limited in this embodiment, and those skilled in the art can select the specific number of the valve body parts 110 according to the usage requirements.

[0078] The air inlets 101 of each valve body part 110 can be communicated with each other or separated. The communication state of the air inlets 101 of each valve body part 110 is not limited in this embodiment. The air outlets 102 of each valve body part 110 are independent of each other, and one-way valve plates are correspondingly arranged at the air outlets 102 of each valve body part 110. The number of one-way valve plates arranged at the air outlets 102 of each valve body part 110 can be the same or different; the arrangement manners of the one-way valve plates arranged at the air outlets 102 of each valve body part 110 can be the same or different; the covering ranges and weights of each one-way valve plate arranged at the air outlets 102 of each valve body part 110 can be the same or different. That is, the one-way valve plates arranged at the air outlets 102 of each valve body part 110 can be the same or different.

[0079] As Figure 8 shown, air outlets 102 are arranged on both sides of the valve body part 110 along the second direction. The first direction is perpendicular to the second direction, and the air outlets 102 on both sides of the valve body part 110 are both communicated with the air inlet 101 of the valve body part 110. The air outlets 102 on both sides of the valve body part 110 can be symmetrically arranged along the central plane of the valve body part 110, and the central plane of the valve body part 110 is the central plane in the second direction. In this embodiment, by arranging air outlets 102 on both sides of the valve body part 110, the opening area of the air outlets 102 on the valve body part 110 can be further increased, which is beneficial to reducing the EGR exhaust gas resistance and improving the engine EGR rate ability.

[0080] The air flow direction at the air inlet 101 forms an obtuse angle with the air flow direction at the air outlet 102, that is, the plane where the air outlet 102 is located is an inclined plane, so that the planes where the air outlets 102 on both sides of the valve body part 110 are located form an acute angle. With such a setting, the air flow turning angle is small, preventing the air flow from needing to make a right-angle turn to pass through the one-way valve, and reducing the air resistance.

[0081] As Figure 17 and Figure 18 shown, the reset member 600 is a door closer. A valve piece connection part is provided on the one-way valve piece, and a valve body connection part is provided on the valve body part 110. One end of the door closer is connected to the valve piece connection part, and the other end is connected to the valve body connection part. As Figure 11 and Figure 13 shown, the valve piece connection part on the first valve piece 200 is the first valve piece connection part 201, and the valve piece connection part on the second valve piece 400 is the second valve piece connection part 401.

[0082] The one-way valve piece can overcome the opening force of the door closer under the action of the pressure difference before and after the one-way valve piece, realize the opening of the one-way valve piece, and use the cam device and hydraulic cylinder of the door closer to realize reset, so that the one-way valve piece automatically closes. At present, door closers are widely used in the automatic closing of doors and windows. In this embodiment, only the door closer is applied to the one-way valve to realize the automatic closing of the one-way valve piece. The specific structure and closing principle of the door closer are prior arts and will not be elaborated herein.

[0083] The door closer has a certain opening pressure. Since the EGR valve cannot achieve zero leakage, when the exhaust pressure is relatively high, the EGR valve will leak some gas into the EGR system. Due to the relatively thin one-way valve piece of the one-way valve in the traditional EGR system, the leaked EGR waste gas will enter the intake side through the one-way valve and participate in combustion, resulting in the engine emissions exceeding the standard. Because the door closer of the one-way valve in this application has a certain opening pressure, the leaked EGR waste gas is small in volume and is not sufficient to push the one-way valve piece to open, ensuring that the EGR waste gas will not leak to the intake side. In this embodiment, the maximum opening angle of each one-way valve piece can be limited by the door closer. Of course, other limit members can also be provided to limit the maximum opening angle of each one-way valve piece.

[0084] As Figure 21 shown, the embodiment of the present application also discloses an EGR system. The EGR system includes an EGR pipeline. One end of the EGR pipeline is an exhaust side connection end, and the other end is an intake side connection end, so that one end of the EGR system can be connected to the exhaust pipeline of the engine body 01, and the other end is connected to the intake pipeline of the engine body 01. Figure 21 The gas in the pipeline shown by the thick solid line is high-temperature gas, and the gas in the pipeline shown by the thin solid line is low-temperature gas.

[0085] In the direction from the exhaust side connection end to the intake side connection end, at least an EGR valve 02 and a check valve 03 disclosed in the above embodiment are connected in series on the EGR pipeline. Since the EGR system disclosed in the embodiment of the present application has the above check valve 03, it has all the technical effects of the above check valve 03, which will not be elaborated herein. An EGR cooler 04 is also provided between the EGR valve 02 and the check valve 03 on the EGR pipeline. The main function of the EGR cooler 04 is to reduce the combustion chamber temperature by cooling the recirculated exhaust gas, thereby reducing the emission of nitrogen oxides (NOx) in the exhaust gas and optimizing the environmental performance of the engine. The embodiment of the present application also discloses an engine, including the EGR system disclosed in the above embodiment. Since it has the above EGR system, the engine disclosed in the embodiment of the present application has all the technical effects of the above EGR system, which will not be elaborated herein.

[0086] It should be noted that the engine can be a diesel engine, a gasoline engine, a gas engine (not limited to natural gas engines and hydrogen internal combustion engines), etc. Of course, it can also be an engine with multiple fuel combustion, including but not limited to an engine with gasoline and methanol mixed combustion, an engine with natural gas and hydrogen mixed combustion, etc.

[0087] As shown in the present application and the claims, unless the context clearly indicates an exception, words such as "a", "an", "one" and / or "the" are not specifically singular and may also include plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. Elements defined by the statement "including one..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0088] In the description of the present application, unless otherwise clearly defined, words such as "set", "installed", "connected" should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above words in the present application in combination with the specific content of the technical solution.

[0089] In this specification, the various embodiments are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0090] Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application. It should be pointed out that for those of ordinary skill in the art in the technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A one-way valve, used for sealing and communicating with a controlled pipeline, characterized in that: The one-way valve body (100) comprises at least one valve body portion (110), the valve body portion (110) being provided with an air flow channel for communicating with the controlled pipeline, one end of the air flow channel being an air flow inlet (101) and the other end being an air flow outlet (102); The air flow outlet (102) is provided with at least two one-way valve discs, each of which is rotatably engaged with the valve body (110), and a free end of each of which is connected to the valve body (110) via a reset member (600), at least two of which are arranged in different pressure areas of the air flow outlet (102), and an opening resistance of the one-way valve disc corresponding to an area with a high outlet pressure is greater than an opening resistance of the one-way valve disc corresponding to an area with a low outlet pressure.

2. The one-way valve according to claim 1, characterized in that: Each of the air flow outlets (102) is provided with two one-way valve discs, namely a first valve disc (200) and a second valve disc (400), and the rotation centers of the first valve disc (200) and the second valve disc (400) are coaxially arranged.

3. The one-way valve according to claim 2, characterized in that: The hinged end of the first valve plate (200) is provided with a first hinge shaft (202), and the hinged end of the second valve plate (400) is provided with a second hinge shaft (402); the first hinge shaft (202) and the second hinge shaft (402) are nested and rotatably supported on a support portion (300) on the valve body portion (110).

4. The one-way valve according to claim 3, characterized in that: One of the first hinge shaft (202) and the second hinge shaft (402) is a central shaft, and the other is a tubular shaft, and the tubular shaft is sleeved on the outside of the central shaft; The support portion (300) is provided with a central hole (302) that matches the central axis, and an annular hole (303) that matches the tube body axis.

5. The one-way valve according to claim 4, characterized in that: The length of the central axis is W1a, the length of the tube body axis is W2a, and W1a≤W2a.

6. The one-way valve according to claim 4, characterized in that: The length of the first hinge shaft (202) is W1a, the dimension of the first valve plate (200) in the axial direction of the first hinge shaft (202) is W1, then (W1a-W1) / W1=0.3-0.4; and / or, The length of the second hinge shaft (402) is W2a, and the dimension of the second valve plate (400) in the axial direction along the second hinge shaft (402) is W2, then (W2a-W2) / W2=0.3-0.

4.

7. The one-way valve according to claim 4, characterized in that: The first hinge axis (202) is a central axis, and the second hinge axis (402) is a tube body axis; The tube body shaft has a bypass opening (4021) in the circumferential direction for bypassing the first valve plate (200), and the bypass opening (4021) extends from one end of the tube body shaft to the other end, and the center angle of the annular hole (303) is greater than the center angle of the tube body shaft.

8. The one-way valve according to claim 7, characterized in that: The central angle of the annular hole (303) is less than 360°.

9. The one-way valve according to any one of claims 2 to 8, characterized in that: The rotation centers of the first valve plate (200) and the second valve plate (400) are located in the middle area of ​​the air flow outlet (102).

10. The one-way valve according to any one of claims 2 to 8, characterized in that: The first valve plate (200) is closer to the middle area in the airflow direction than the second valve plate (400); The coverage area of ​​the first valve sheet (200) is greater than the coverage area of ​​the second valve sheet (400), and / or the weight of the first valve sheet (200) is greater than the weight of the second valve sheet (400).

11. The one-way valve according to claim 10, characterized in that: The thickness of the first valve sheet (200) is A, the thickness of the second valve sheet (400) is B, the dimension of the first valve sheet (200) along the arrangement direction of the first valve sheet (200) and the second valve sheet (400) is L1, and the dimension of the second valve sheet (400) along the arrangement direction of the first valve sheet (200) and the second valve sheet (400) is L2; Then B=(0.8-0.9)A, L2=(0.3-0.4)L1.

12. The one-way valve according to any one of claims 1 to 8, characterized in that: The valve body parts (110) are multiple and arranged along the first direction, and the air flow inlets (101) of the valve body parts (110) are connected or separated.

13. The one-way valve according to claim 12, characterized in that: The air flow outlets (102) are provided on both sides of the valve body (110) along a second direction, the first direction is perpendicular to the second direction, and the air flow outlets (102) on both sides of the valve body (110) are connected to the air flow inlet (101) of the valve body (110).

14. The one-way valve according to claim 13, characterized in that: The airflow direction at the airflow inlet (101) and the airflow direction at the airflow outlet (102) form an obtuse angle.

15. The one-way valve according to any one of claims 1 to 8, characterized in that: The reset member (600) is a door closer, the one-way valve disc is provided with a valve disc connection portion, the valve body portion (110) is provided with a valve body connection portion, one end of the door closer is connected to the valve disc connection portion, and the other end is connected to the valve body connection portion.

16. The one-way valve according to any one of claims 1 to 8, characterized in that: The thickness of the one-way valve plate is 0.9 mm-3 mm.

17. An EGR system, characterized in that: It includes an EGR pipeline, one end of which is an exhaust side connection end, and the other end of which is an intake side connection end; In the direction from the exhaust side connection end to the intake side connection end, the EGR pipeline is connected in series with at least an EGR valve and a one-way valve as described in any one of claims 1 to 16.

18. An engine, characterized in that: Comprising the EGR system of claim 17.

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