An EGR valve with good sealing performance

Abstract

The present invention relates to an EGR valve with good sealing performance, which comprises a valve body, a valve seat, a first valve rod, a driving device, a second valve rod and an impeller. The impeller comprises a plurality of groups of blades arranged at uniform intervals. It is characterized in that: the valve seat comprises an upper connecting body and a lower connecting body; the lower connecting body is provided with an air inlet hole and an exhaust gas cavity; the upper connecting body comprises a first mounting seat, a partition cavity and a second mounting seat; a first sealing groove is arranged on the first mounting seat, a second sealing groove is arranged on the second mounting seat, and a first sealing ring and a second sealing ring are arranged between the valve body and the valve seat. The beneficial effects of the present invention are as follows: an EGR valve with good sealing performance is provided, which is convenient to assemble, does not require large-area coating of grease, is convenient for disassembly and maintenance, and has excellent sealing performance.

Description

Technical Field

[0001] The present invention specifically relates to an EGR valve with good sealing performance. Background Art

[0002] The principle of the exhaust gas recirculation system is to mix a part of the high-temperature exhaust gas discharged from the engine with fresh air and then introduce it into the intake system to participate in re-combustion, thereby improving the combustion performance, reducing the formation of nitrogen oxides and the emission of waste in the engine exhaust gas, and reducing the pollution to the atmosphere. The EGR valve is a device installed on an automobile engine to control when and how much engine exhaust gas enters the intake system. It is the most important and key component in the exhaust gas recirculation module. Whether the EGR valve can work stably and reliably directly affects the operating performance of the engine.

[0003] The EGR valve mainly consists of a valve body and a valve seat. A solenoid valve is installed at the valve body. The solenoid valve is linked with a valve rod. The valve rod extends to the valve seat. A blade linked with the valve rod is arranged at the lower end of the valve seat. After the solenoid valve is powered on, it drives the valve rod to rotate. The valve rod drives the blade to rotate, so as to open the air inlet on the valve seat, thereby realizing the exhaust gas recirculation. However, the existing EGR valves have the following defects:

[0004] Since the contact area between the valve body and the valve seat is relatively large, conventional technical means usually use fasteners such as screws and bolts to connect the valve body and the valve seat. In order to ensure its sealing performance, the joint end face between the valve body and the valve seat is coated with grease to achieve the sealing performance. Whether it is manually applied or machine-applied, it is impossible to evenly distribute the grease smoothly on all parts of the joint end face between the valve body and the valve seat. Therefore, the sealing performance is not good. Further, due to the continuous vibration of the vehicle body during driving, the grease is not in a completely solid state, and it will accumulate and shake during continuous vibration, which will cause the grease to be unable to be evenly distributed on all parts of the joint end face between the valve body and the valve seat. Therefore, the sealing performance is poor. Therefore, it is necessary to improve the upper cover and the valve seat to improve the sealing performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an EGR valve with good sealing performance in view of the above-mentioned deficiencies of the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions: An EGR valve with good sealing performance, comprising a valve body and a valve seat detachably connected to the valve body. A rotatable first valve stem and a driving device for controlling the rotation and stop of the first valve stem are provided inside the valve body. A rotatable second valve stem is provided inside the valve seat. One end of the second valve stem is detachably connected to the end of the first valve stem, and an impeller is fixedly provided at the other end. The impeller includes several groups of blades arranged at uniform intervals. It is characterized in that the valve seat includes an upper connecting body detachably connected to the valve body and a lower connecting body for guiding and transporting exhaust gas. Corresponding to each group of blades, a group of air inlet holes are provided at the end of the lower connecting body. An exhaust gas cavity with one end connected to the air inlet hole in a conducting manner and the other end being open is further provided inside the lower connecting body. The upper connecting body includes a first mounting seat detachably and sealingly connected to the valve seat and a second mounting seat pivotally connected to the second valve stem. A partition cavity is provided between the first mounting seat and the second mounting seat. An open first sealing groove facing the valve seat is provided on the first mounting seat. The first sealing groove is a closed ring with all parts communicating with each other and both ends connected. An open second sealing groove facing the valve seat is provided on the second mounting seat. The second sealing groove is a closed ring with all parts communicating with each other and both ends connected. A first sealing ring and a second sealing ring are provided between the valve body and the valve seat. The upper part of the first sealing ring is in contact connection with the valve body, and the lower part is fitted into the first sealing groove. The upper part of the second sealing ring is in contact connection with the valve body, and the lower part is fitted into the second sealing groove.

[0007] By adopting the above technical solutions, the structures of the valve body and the valve seat are improved. By providing the first sealing groove and the second sealing groove and using the first sealing ring and the second sealing ring as sealing connectors, the sealing performance of the EGR valve can be effectively improved. Further, the upper connecting body is set in the form of the first mounting seat and the second mounting seat, and a partition cavity is provided between the two mounting seats, greatly reducing the contact area at the connection between the valve seat and the valve body, thereby reducing the number of sealing points to be sealed. The first sealing ring and the second sealing ring respectively form two sealing lines of defense, and excellent sealing effects can be achieved. Moreover, the partition cavity can serve as the third sealing line of defense between the two sealing lines of defense. Even if a small leakage accidentally occurs at the first sealing ring, the leaked medium will be temporarily stored in the partition cavity and will not enter the second sealing ring. After setting the partition cavity, the overall weight of the EGR can be further reduced, which conforms to the development concept of automotive lightweight. In summary, compared with the existing EGR valves, it is convenient to assemble, does not require large-area coating of grease, is easy to disassemble and repair, and has excellent sealing performance.

[0008] The above EGR valve with good sealing performance can be further configured as follows: A linkage component is provided between the first valve stem and the second valve stem. The linkage component includes an upper coupling fixedly connected to the first valve stem relatively, a lower coupling fixedly connected to the second valve stem relatively, and the linkage component further includes a coupling turntable. The upper end surface of the coupling turntable is provided with a transverse connection groove arranged radially, and the lower end surface is provided with a longitudinal connection groove arranged perpendicular to the transverse connection groove. The upper coupling is fixedly connected to the coupling turntable through the transverse connection groove, and the lower coupling is fixedly connected to the coupling turntable through the longitudinal connection groove. The second valve stem is linked with a reset component.

[0009] Adopting the above technical solution, by arranging a linkage component between the first valve stem and the second valve stem, not only can force transmission be realized to correctly control the rotation of the impeller, so as to open the air inlet hole to realize exhaust gas circulation, but also under the action of the reset part in the linkage component, it is convenient for the impeller to reset after the EGR valve stops working and close the air inlet hole; among them, the coupling turntable is used to link the upper coupling and the lower coupling to realize their synchronous rotation.

[0010] The above EGR valve with good sealing performance can be further configured as follows: The reset component includes a torsion spring. One end of the lower coupling is provided with a plugging groove for the end part of the torsion spring to be plugged in, and the other end is provided with an extending body extending towards the distance. A sliding guiding groove for sliding connection with the torsion spring is provided below the extending body.

[0011] Adopting the above technical solution, the torsion spring has good resilience performance and can control the impeller more sensitively; by adding a sliding guiding groove, when the EGR valve is opened for work, the driving device drives the first valve stem to rotate, and the first valve stem drives the second valve stem to rotate through the lower coupling, the coupling turntable and the upper coupling. At the same time, since one end of the torsion spring is inserted into the plugging groove, the whole torsion spring is twisted and stores a reset force, and each turn of the torsion spring is guided and twisted under the action of the sliding guiding groove, improving the overall torsion change law of the torsion spring and avoiding self-sticking of the torsion spring.

[0012] The above EGR valve with good sealing performance can be further configured as follows: An arc-shaped limiting groove distributed on one side of the coupling turntable is provided on the second mounting seat, and the extending body is movably distributed in the arc-shaped limiting groove.

[0013] Adopting the above technical solution, the arc-shaped limiting groove is used to limit the rotation direction of the impeller to avoid excessive rotation of the impeller, and it can rotate within the range where the air inlet is completely opened and completely closed.

[0014] The above EGR valve with good sealing performance can be further configured as follows: A plurality of groups of first sealing inserts arranged at intervals are provided on the outer periphery of the first sealing ring, and a plurality of groups of second sealing inserts arranged at intervals are provided on the outer periphery of the second sealing ring.

[0015] With the above technical solution, a first sealing insert block and a second sealing insert block are added to improve the insertion tightness of the first sealing ring and the second sealing ring with the first sealing groove and the second sealing groove respectively, and prevent the first sealing ring and the second sealing ring from shaking up and down, so as to better achieve sealing.

[0016] The above EGR valve with good sealing performance can be further configured as follows: for each group of air intake holes, the lower connecting body is respectively provided with a group of guiding ring strips that surround the air intake holes and protrude outward.

[0017] With the above technical solution, the guiding ring strips are arranged outside the air intake holes, which is convenient for processing. Mainly, the guiding ring strips are used to contact the blades instead of the lower end face of the lower connecting body. When the EGR valve is not working, in order to ensure that the blades can better cover the air intake holes, only the flatness of the end face of the guiding ring strips needs to be processed during processing. Therefore, the processing difficulty is greatly reduced. If the guiding ring strips are not provided, in order to prevent the blades from interfering with the lower end face of the lower connecting body during the process of covering and opening the air intake holes, it is necessary to ensure that the overall lower end face of the lower connecting body has a high flatness of the end face, which undoubtedly greatly improves the processing difficulty. However, in this application, by setting the guiding ring strips, this technical problem can be solved. Only the end faces of each group of guiding ring strips need to be processed reasonably, reducing the processing area, and the processing difficulty is greatly reduced. Moreover, when the impeller is in the working state, the blades will not interfere with the lower end face of the lower connecting body, which can further improve the rotational stability of the impeller and the working reliability.

[0018] The above EGR valve with good sealing performance can be further configured as follows: the driving device includes a housing. One end of the housing is detachably connected with an end cover, and a coil rotor assembly is arranged inside. The other end is detachably and fixedly connected with the valve body. A plurality of groups of clamping blocks are arranged on the outer periphery of the housing. For each group of clamping blocks, the end cover is respectively provided with a group of clamping grooves. The upper end of the clamping block is provided with a first inclined surface, and the inner periphery of the end cover is provided with a second inclined surface.

[0019] With the above technical solution, the housing is used to install the coil rotor assembly, and the end cover is used to seal the housing to prevent the coil rotor assembly from being exposed to the air and protect the coil rotor assembly. Further, the clamping blocks are arranged on the housing and the clamping grooves are arranged on the end cover. The clamping blocks and the clamping grooves cooperate with each other, and the housing and the end cover can be detachably and fixedly connected without using fasteners such as screws, and the operation is convenient, just press down the end cover. Further, the first inclined surface and the second inclined surface are added, and the edge clamping blocks enter the clamping grooves. Among them, the coil rotor assembly is a partial principle structure of the motor. When it is in the energized state, it can realize controlling the rotation of the first valve rod. This is the prior art and will not be elaborated in this application, but those skilled in the art also know it.

[0020] The present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0021] Figure 1 Schematic diagram of the assembled state of the embodiment of the present invention;

[0022] Figure 2 Explosion diagram of the embodiment of the present invention;

[0023] Figure 3 Schematic diagram of the valve seat structure of the embodiment of the present invention Figure 1 ;

[0024] Figure 4 Schematic diagram of the valve seat structure of the embodiment of the present invention Figure 2 ;

[0025] Figure 5 Schematic diagram of the connection state of the linkage component, the first valve stem and the second valve stem in the embodiment of the present invention;

[0026] Figure 6 Partial explosion diagram of the linkage component in the embodiment of the present invention. Specific embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Valve body 1, valve seat 2, upper connecting body 21, first mounting seat 211, second mounting seat 212, partition cavity 213, first sealing groove 214, second sealing groove 215, arc-shaped limiting groove 216, lower connecting body 22, intake hole 221, exhaust gas cavity 222, guide ring strip 223, driving device 3, housing 31, clamping block 311, second inclined surface 312, end cover 32, clamping groove 321, first inclined surface 322, first valve stem 4, second valve stem 5, blade 6, first sealing ring 7, first sealing insert block 71, second sealing ring 8, second sealing insert block 81, linkage component 9, lower coupling 91, insertion slot 911, extension body 912, sliding guide groove 913, coupling turntable 92, transverse connecting groove 921, longitudinal connecting groove 922, upper coupling 93, torsion spring 94

[0029] As Figures 1 to 6An EGR valve with good sealing performance as shown in the figure includes a valve body 1 and a valve seat 2 detachably connected to the valve body 1. A rotatable first valve stem 4 and a driving device 3 for controlling the rotation and stop of the first valve stem 4 are provided inside the valve body 1. A rotatable second valve stem 5 is provided inside the valve seat 2. One end of the second valve stem 5 is detachably connected to the end of the first valve stem 4, and an impeller is fixedly provided at the other end. The impeller includes 3 groups of blades 6 arranged at uniform intervals. The valve seat 2 includes an upper connecting body 21 detachably connected to the valve body 1 and a lower connecting body 22 for guiding and transporting exhaust gas. A set of intake holes 221 are respectively provided at the end of the lower connecting body 22 corresponding to each group of blades 6. An exhaust gas cavity 222 with one end communicating with the intake holes 221 and the other end being open is also provided inside the lower connecting body 22. The upper connecting body 21 includes a first mounting seat 211 detachably and sealingly connected to the valve seat 2 and a second mounting seat 212 pivotally connected to the second valve stem 5. A partition cavity 213 is provided between the first mounting seat 211 and the second mounting seat 212. By setting the upper connecting body 21 in the form of the first mounting seat 211 and the second mounting seat 212 and providing the partition cavity 213 between the two mounting seats, the contact area at the connection between the valve seat 2 and the valve body 1 is greatly reduced, thereby reducing the number of sealing points that need to be sealed.

[0030] A first sealing groove 214 with an open end facing the valve seat 2 is provided on the first mounting seat 211. The first sealing groove 214 is a closed ring with all parts communicating with each other and both ends connected. A second sealing groove 215 with an open end facing the valve seat 2 is provided on the second mounting seat 212. The second sealing groove 215 is a closed ring with all parts communicating with each other and both ends connected. A first sealing ring 7 and a second sealing ring 8 are provided between the valve body 1 and the valve seat 2. The upper part of the first sealing ring 7 is in contact with the valve body 1, and the lower part is fitted into the first sealing groove 214. The upper part of the second sealing ring 8 is in contact with the valve body 1, and the lower part is fitted into the second sealing groove 215. By improving the structures of the valve body 1 and the valve seat 2, through the provision of the first sealing groove 214 and the second sealing groove 215 and the use of the first sealing ring 7 and the second sealing ring 8 as sealing connectors, the sealing performance of the EGR valve can be effectively improved. Further, two sealing lines are respectively formed by the first sealing ring 7 and the second sealing ring 8, achieving an excellent sealing effect. Moreover, the partition cavity 213 can serve as a third sealing line between the two sealing lines. Even if a small leakage occurs accidentally at the first sealing ring 7, the leaked medium will be temporarily stored in the partition cavity 213 and will not enter the second sealing ring 8. After the partition cavity 213 is provided, the overall weight of the EGR can be further reduced, which conforms to the development concept of automotive lightweighting.

[0031] A linkage component 9 is provided between the first valve stem 4 and the second valve stem 5. The linkage component 9 includes an upper coupling 93 fixedly connected to the first valve stem 4, a lower coupling 91 fixedly connected to the second valve stem 5, and the linkage component 9 further includes a coupling turntable 92. The upper end surface of the coupling turntable 92 is provided with a transverse connection groove 921 arranged radially, and the lower end surface is provided with a longitudinal connection groove 922 arranged perpendicular to the transverse connection groove 921. The upper coupling 93 is fixedly connected to the coupling turntable 92 through the transverse connection groove 921, and the lower coupling 91 is fixedly connected to the coupling turntable 92 through the longitudinal connection groove 922. The second valve stem 5 is linked with a reset component. Arranging the linkage component 9 between the first valve stem 4 and the second valve stem 5 can not only achieve force transmission, correctly control the rotation of the impeller, so as to open the air inlet hole 221 to realize the exhaust gas circulation, but also facilitate the reset of the impeller after the EGR valve stops working and close the air inlet hole 221 under the action of the reset part in the linkage component 9. Among them, the coupling turntable 92 is used to link the upper coupling 93 and the lower coupling 91 to realize the synchronous rotation of the two.

[0032] The reset component includes a torsion spring 94. One end of the lower coupling 91 is provided with a plug-in groove 911 for the end of the torsion spring 94 to be inserted, and the other end is provided with an extension body 912 extending towards the distance. A sliding guide groove 913 for sliding connection with the torsion spring 94 is arranged below the extension body 912. The torsion spring 94 has good resilience performance and can control the impeller more sensitively. The sliding guide groove 913 is added. When the EGR valve is opened and working, the driving device 3 drives the first valve stem 4 to rotate. The first valve stem 4 drives the second valve stem 5 to rotate through the lower coupling 91, the coupling turntable 92, and the upper coupling 93. At the same time, since one end of the torsion spring 94 is inserted into the plug-in groove 911, the whole torsion spring 94 is twisted and stores a reset force. Each turn of the torsion spring 94 is guided and twisted under the action of the sliding guide groove 913, improving the overall torsion change law of the torsion spring 94 and avoiding jamming of the torsion spring 94 itself.

[0033] An arc-shaped limiting groove 216 distributed on one side of the coupling turntable 92 is arranged on the second mounting seat 212. The extension body 912 is movably distributed in the arc-shaped limiting groove 216. The arc-shaped limiting groove 216 is used to limit the rotation direction of the impeller to avoid excessive rotation of the impeller, and it can rotate within the range where the air inlet is fully opened and fully closed.

[0034] Multiple groups of first sealing blocks 71 arranged at intervals are provided on the outer periphery of the first sealing ring 7, and multiple groups of second sealing blocks 81 arranged at intervals are provided on the outer periphery of the second sealing ring 8. The first sealing blocks 71 and the second sealing blocks 81 are added to improve the insertion tightness of the first sealing ring 7 and the second sealing ring 8 with the first sealing groove 214 and the second sealing groove 215 respectively, and avoid the up and down shaking of the first sealing ring 7 and the second sealing ring 8, so as to better achieve sealing.

[0035] The lower connecting body 22 is respectively provided with a set of guiding ring strips 223 that surround the intake holes 221 and protrude outwardly corresponding to each set of intake holes 221. The guiding ring strips 223 are arranged outside the intake holes 221, which is convenient for processing. Mainly, the guiding ring strips 223 are used to contact the blades 6 instead of the lower end surface of the lower connecting body 22. When the EGR valve is not working, in order to ensure that the blades 6 can better cover the intake holes 221, during processing, only the flatness of the end surface of the guiding ring strips 223 needs to be processed. Therefore, the processing difficulty is greatly reduced. If the guiding ring strips 223 are not provided, in order to prevent the blades 6 from interfering with the lower end surface of the lower connecting body 22 during the process of covering and opening the intake holes 221, it is necessary to ensure that the entire lower end surface of the lower connecting body 22 has a high flatness of the end surface, which undoubtedly greatly improves the processing difficulty. However, in this application, by providing the guiding ring strips 223, this technical problem can be solved. Only the end surfaces of each group of guiding ring strips 223 need to be processed reasonably, reducing the processing area, and the processing difficulty is greatly reduced. Moreover, when the impeller is in the working state, the blades 6 will not interfere with the lower end surface of the lower connecting body 22, which can further improve the rotational stability of the impeller and the working reliability.

[0036] The driving device 3 includes a housing 31. One end of the housing 31 is detachably connected with an end cover 32, and a coil rotor assembly is arranged inside. The other end is detachably and fixedly connected with the valve body 1. Four groups of clamping blocks 311 are arranged on the outer periphery of the housing 31. A set of clamping grooves 321 are respectively arranged on the end cover 32 corresponding to each group of clamping blocks 311. A first inclined surface 322 is arranged at the upper end of the clamping block 311, and a second inclined surface 312 is arranged on the inner periphery of the end cover 32. The housing 31 is used to install the coil rotor assembly, and the end cover 32 is used to seal the housing 31 to prevent the coil rotor assembly from being exposed to the air and protect the coil rotor assembly. Further, the clamping blocks 311 are arranged on the housing 31 and the clamping grooves 321 are arranged on the end cover 32. The clamping blocks 311 and the clamping grooves 321 cooperate with each other, and the housing 31 and the end cover 32 can be detachably and fixedly connected without fasteners such as screws, and the operation is convenient. Just press down the end cover 32. Further, the first inclined surface 322 and the second inclined surface 312 are added, and the edge clamping blocks 311 enter the clamping grooves 321. Among them, the coil rotor assembly is a partial principle structure of the motor. When in the energized state, the rotation of the first valve rod 4 can be controlled, which is the prior art. Without further elaboration in this application, those skilled in the art also know.

[0037] Compared with the existing EGR valve, this specific embodiment is convenient for assembly, does not require large-area coating of lubricating grease, is convenient for disassembly and maintenance, and has excellent sealing performance.

[0038] Working principle of this specific embodiment: A plug for power supply is provided on the end cover 32. After being powered on, the coil rotor assembly drives the first valve rod 4 to rotate. The first valve rod 4 drives the upper coupling 93 to rotate. The coupling turntable 92 rotates following the upper coupling 93, and then the lower coupling 91 rotates following the coupling turntable 92. Therefore, the second valve rod 5 also keeps rotating following the lower coupling 91 (meanwhile, the torsion spring 94 twists to accumulate the restoring force. Once the work stops, the torsion spring 94 drives the impeller to restore and cover the air inlet hole 221). The impeller rotates following the second valve rod 5, and the air inlet hole 221 is opened, so that the waste gas circulation work can proceed smoothly. By changing the voltage magnitude or the power-on time, the size of the air inlet hole 221 can be changed, and the waste gas circulation efficiency changes to adapt to different working conditions.

Claims

1. An EGR valve with good sealing performance, comprising a valve body and a valve seat detachably connected to the valve body. A rotatable first valve stem and a driving device for controlling the rotation and stop of the first valve stem are provided inside the valve body. A rotatable second valve stem is provided inside the valve seat. One end of the second valve stem is detachably connected to the end of the first valve stem, and an impeller is fixedly provided at the other end. The impeller comprises a number of groups of blades arranged at uniform intervals. Characterized in that: The valve seat comprises an upper connecting body detachably connected to the valve body and a lower connecting body for guiding and transporting exhaust gas; A set of air inlet holes are respectively provided at the end of the lower connecting body corresponding to each group of blades. An exhaust gas cavity with one end communicated with the air inlet holes and the other end being open is further provided inside the lower connecting body; The upper connecting body comprises a first mounting seat detachably and sealingly connected to the valve seat and a second mounting seat pivotally connected to the second valve stem. A partition cavity is provided between the first mounting seat and the second mounting seat; A first sealing groove opening towards the valve seat is provided on the first mounting seat. The first sealing groove is a closed ring with all parts communicating with each other and both ends connected. A second sealing groove opening towards the valve seat is provided on the second mounting seat. The second sealing groove is a closed ring with all parts communicating with each other and both ends connected. A first sealing ring and a second sealing ring are provided between the valve body and the valve seat. The upper part of the first sealing ring abuts against the valve body, and the lower part is fitted into the first sealing groove. The upper part of the second sealing ring abuts against the valve body, and the lower part is fitted into the second sealing groove; The driving device comprises a housing. One end of the housing is detachably connected with an end cover, and a coil rotor assembly is provided inside. The other end is detachably and fixedly connected to the valve body. A number of groups of clamping blocks are provided on the outer periphery of the housing. A set of clamping grooves are respectively provided on the end cover corresponding to each group of clamping blocks. A first inclined surface is provided at the upper end of the clamping block, and a second inclined surface is provided on the inner periphery of the end cover.

2. An EGR valve with good sealing performance according to claim 1, Characterized in that: A linkage component is provided between the first valve stem and the second valve stem. The linkage component comprises an upper coupling fixedly connected to the first valve stem and a lower coupling fixedly connected to the second valve stem. The linkage component further comprises a coupling turntable. A transverse connecting groove arranged along the radial direction is provided on the upper end surface of the coupling turntable, and a longitudinal connecting groove arranged perpendicular to the transverse connecting groove is provided on the lower end surface. The upper coupling is fixedly connected to the coupling turntable through the transverse connecting groove, and the lower coupling is fixedly connected to the coupling turntable through the longitudinal connecting groove. The second valve stem is linked with a reset component.

3. An EGR valve with good sealing performance according to claim 2, Characterized in that: The reset component comprises a torsion spring. A plugging groove for inserting the end of the torsion spring is provided at one end of the lower coupling, and an extending body extending towards the distance is provided at the other end. A sliding guiding groove for slidingly connecting with the torsion spring is provided below the extending body.

4. An EGR valve with good sealing performance according to claim 3, Characterized in that: An arc-shaped limiting groove distributed on one side of the coupling turntable is provided on the second mounting seat. The extending body is movably distributed in the arc-shaped limiting groove.

5. An EGR valve with good sealing performance according to any one of claims 1 to 4, characterized in that: a plurality of groups of first sealing inserts arranged at intervals are provided on the outer periphery of the first sealing ring, and a plurality of groups of second sealing inserts arranged at intervals are provided on the outer periphery of the second sealing ring.

6. An EGR valve with good sealing performance according to any one of claims 1 to 4, characterized in that: the lower connecting body is respectively provided with a group of guiding ring strips that surround the intake holes and protrude outward for each group of intake holes.

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