Rotary turbine bypass valve and turbocharger

Abstract

The present invention provides a rotary turbine bypass valve and a turbocharger. In the bypass valve, along the extension direction of the flow channel from the intake flange to the vortex tongue, the flow channel area of ​​the front flow channel is linearly reduced or nearly linearly reduced, and the change range of the fluid direction of the front flow channel is within 30 degrees. The bypass valve helps to suppress vortex turbulence.

Description

Technical Field

[0001] The present invention belongs to the technical field of turbochargers, and in particular relates to a rotary turbine bypass valve and a turbocharger. Background Art

[0002] This section is intended to provide a background or context to the embodiments recited in the claims. No admission is made that the description herein is prior art by inclusion in this section.

[0003] A turbine is a well-known device for converting the kinetic energy of a flowing gas into useful work. Known turbines convert the kinetic energy of a flowing gas into the rotational kinetic energy of a turbine wheel of the turbine. The rotation of the turbine wheel may be transmitted by a suitable linkage to any device suitable for doing useful work. Examples of such devices include generators (so that the turbine forms part of a power turbine) and compressors (so that the turbine forms part of a turbocharger).

[0004] The turbine of a turbocharger receives exhaust gas from an internal combustion engine, thereby rotating the turbine wheel of the turbocharger to drive the rotation of the compressor wheel. The compressor wheel draws in gas and pressurizes the gas so that the gas pressure at the compressor output is increased compared to the gas at the inlet of the compressor. The output of the compressor of the turbocharger can be fed to the inlet of the internal combustion engine of which the turbocharger forms a part.

[0005] In some applications of turbines, a turbine bypass valve may be required to allow exhaust gas produced by an engine to which the turbine is attached to bypass the turbine so that the exhaust gas flows to the engine's exhaust aftertreatment without passing through the turbine wheel.

[0006] Some turbine bypass valves known to the inventors are rotary valves. The rotary valve includes a housing defining a valve chamber at the junction of an inlet port, an outlet port, and a bypass port. A valve rotor is supported to rotate within the valve chamber. The valve rotor is rotatable about a valve axis between a first position in which the valve rotor allows airflow through the bypass port and a second position in which the valve rotor blocks airflow through the bypass port.

[0007] Some rotary valves known to the inventor have housings formed by a portion of a turbine housing. In order to mount the valve rotor in the turbine housing, two holes need to be opened in the turbine housing, one relatively large hole and one relatively small hole. The valve rotor is inserted into the valve chamber from the large hole and one end passes through the small hole, and then the large hole is sealed with a cover plate. The portion of the valve rotor passing through the small hole is used to connect to an actuating structure so that the valve rotor is driven to rotate by the actuating mechanism.

[0008] When the exhaust gas discharged from the engine exhaust manifold flows into the turbine housing, it is inevitable that vortex turbulence will be generated, which will reduce the efficiency of the exhaust gas in working on the turbine impeller. Summary of the invention

[0009] The present disclosure provides a rotary turbine bypass valve and a turbocharger.

[0010] The present disclosure adopts the following technical solution: a rotary turbine bypass valve, comprising: a turbine casing, a valve rotor and a cover plate;

[0011] The turbine housing includes a main flow channel and a bypass flow channel, the main flow channel includes at least one front flow channel defined by an intake flange and a vortex tongue and a rear flow channel defined by the vortex tongue and an exhaust port of the main flow channel, the bypass flow channel is connected to the main flow channel at the position of the front flow channel, and a valve chamber is formed at the connection between the bypass flow channel and the front flow channel, and the valve rotor is arranged in the valve chamber in a manner that it can rotate freely along a rotation axis;

[0012] The valve rotor comprises a first end, a middle portion, and a second end which are sequentially arranged along an extension direction of the rotation axis, the smallest enclosing cylinders of the first end, the middle portion, and the second end all have the rotation axis as the axis, the diameter of the smallest enclosing cylinder of the middle portion of the valve rotor is larger than the diameters of the smallest enclosing cylinders of the first end and the second end, the turbine housing is provided with a first through hole and a second through hole which are opposite to each other at a position opposite to the front end flow passage, the first end of the valve rotor passes through the first through hole to be connected to an actuating mechanism which drives the valve rotor to rotate around the rotation axis, the cover plate covers the second through hole and forms a receiving groove for receiving the second end of the valve rotor;

[0013] The middle part of the valve rotor is provided with at least one rotor flow channel, each of the rotor flow channels is formed with a first opening and a second opening on the side of the middle part, and the proportion of the airflow received by the rear end flow channel and the bypass flow channel is allocated by rotating the valve rotor, wherein the rotor flow channel is connected with the front end flow channel in a one-to-one correspondence;

[0014] Along the extension direction of the flow channel from the air inlet flange to the vortex tongue, the flow channel area of ​​the front end flow channel is linearly reduced or nearly linearly reduced, and the change range of the fluid direction of the front end flow channel is within 30°.

[0015] Optionally, the free end of the vortex tongue is chamfered, the turbine casing is used to place a turbine impeller, the plane passing through the axis of the turbine impeller and through the center of the chamfered section of the free end of the vortex tongue is a first plane, the area of ​​the cross-section of the front end flow channel perpendicular to its center line and the distance from the center of mass of the cross-section to the first plane change linearly or nearly linearly, and the angle between the tangents of the center line of the front end flow channel at various positions and the tangents of the center line of the front end flow channel at the vortex tongue is less than 30°.

[0016] Optionally, an angle between the tangent lines at various positions of the center line of the front end flow channel and the tangent lines of the center line of the front end flow channel at the vortex tongue is less than 10°.

[0017] Optionally, when the valve rotor rotates to a set state in which the bypass flow channel is closed and the air flow resistance passing through the valve rotor is minimized, in a cross section of the rotary turbine bypass valve perpendicular to the axis of the turbine impeller, an included angle between the tangent lines of the rotor flow channel of the valve rotor and the turbine casing at the junction is in the range of 170° to 180°, and a distance difference between the rotor flow channel of the valve rotor and the turbine casing at the junction to a reference straight line is less than 1 mm, and the reference straight line is a line passing through the intersection of the axis of the turbine casing impeller and the cross section in the cross section and extending in a direction that is the average of the extension direction of the center line of the intake flow channel in the cross section.

[0018] Optionally, when the valve rotor rotates to the set state, in a cross section of the rotary turbine bypass valve perpendicular to the axis of the turbine impeller, an angle between the tangent lines of the rotor flow channel of the valve rotor and the turbine casing at the junction thereof is in the range of 175° to 180°.

[0019] Optionally, in the set state, a plane that is perpendicular to the center line of the front section of the flow channel, intersects the middle part of the valve rotor and is closest to the vortex tongue is a second plane, the area of ​​the main flow channel intercepted by the second plane is a second area, and the orthographic projection area of ​​the opening of the rotor flow channel toward the second plane on the second plane is greater than or equal to the second area. A plane that is perpendicular to the center line of the front section of the flow channel, intersects the middle part of the valve rotor and is farthest from the vortex tongue is a third plane, the area of ​​the main flow channel intercepted by the third plane is a third area, and the orthographic projection area of ​​the opening of the rotor flow channel toward the third plane on the third plane is less than or equal to the third area.

[0020] The present disclosure adopts the following technical solution: a turbocharger, comprising the aforementioned turbine bypass valve.

[0021] Compared with the prior art, the beneficial effect of the present disclosure is that the bypass valve helps to suppress vortex turbulence. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a perspective view of a rotary turbine bypass valve according to an embodiment of the present disclosure, wherein a portion of the turbine casing is removed.

[0023] Figure 2 yes Figure 1 A cross-sectional view of a rotary turbine bypass valve is shown.

[0024] Figure 3a and Figure 3b yes Figure 1 A perspective view of the valve rotor in the rotary turbine bypass valve is shown.

[0025] Figures 4a to 4c yes Figure 1 Schematic diagram of parameter definition of the rotary turbine bypass valve shown.

[0026] Among them, 1. turbine casing; 11, 12, front end flow channel; 13, rear end flow channel outlet; 14, intake flange; 15, rear end flow channel; 16, vortex tongue; 17, bypass flow channel; 2, valve rotor; 21, first end; 22, middle part; 23, second end; 24, first opening; 25, second opening; 3, actuator; 4, cover plate; F1, first plane; F2, second plane; F3, third plane; F4, fourth plane; F5, reference straight line; L0, center line. DETAILED DESCRIPTION

[0027] The present disclosure is further described below in conjunction with the embodiments shown in the accompanying drawings.

[0028] refer to Figures 1 to 4c An embodiment of the present disclosure provides a rotary turbine bypass valve, comprising: a turbine casing 1 , a valve rotor 2 and a cover plate 4 .

[0029] The turbine casing 1 includes a main flow channel and a bypass flow channel 17. The main flow channel includes front end flow channels 11, 12 defined by an intake flange 14 and a vortex tongue 16 and a rear end flow channel 15 defined by the vortex tongue 16 and an exhaust port of the main flow channel. The bypass flow channel 17 is connected to the main flow channel at the position of the front end flow channels 11, 12, and a valve chamber is formed at the connection between the bypass flow channel 17 and the front end flow channels 11, 12. The valve rotor 2 is arranged in the valve chamber in a manner that it can rotate freely along the rotation axis.

[0030] The intake flange 14 is used to receive gas. When the valve rotor 2 rotates around the rotation axis to a first position, the valve rotor 2 blocks the engine exhaust gas from flowing into the bypass channel 17 and allows the gas to flow into the rear end channel 15. When the valve rotor 2 rotates around the rotation axis to a second position, the valve rotor 2 allows all the gas to flow into the bypass channel 17. The bypass channel 17 and the rear end channel 15 are both used to discharge the gas into the exhaust gas treatment system (not shown).

[0031] When the valve rotor 2 rotates around the rotation axis to an intermediate position between the first position and the second position, the valve rotor 2 allows part of the gas to flow into the rear end flow passage 15, and another part of the gas to flow into the bypass flow passage 17. The valve rotor 2 can accurately control the proportion of the gas flowing into the rear end flow passage 15, thereby adapting to different working conditions of the engine.

[0032] The exhaust gas flowing out of the bypass flow channel 17 and the rear end flow channel 15 will eventually be discharged into the exhaust gas treatment system. The end of the bypass flow channel 17 can be connected to the rear end flow channel 15 in the turbine housing 1, so that the exhaust gas only flows out from the outlet 13 of the rear end flow channel 15. The exhaust gas can also flow out of the bypass flow channel 17 and merge with the exhaust gas flowing out of the rear end flow channel 15 outside the outlet 13 of the turbine housing 1, and then flow into the exhaust gas treatment system.

[0033] The valve rotor 2 has a first end 21, a middle portion 22, and a second end 23 which are sequentially arranged along an extension direction of the rotation axis, and the smallest surrounding cylinders of the first end 21, the middle portion 22, and the second end 23 all have the rotation axis as an axis. The diameter of the smallest surrounding cylinder of the middle portion 22 is greater than the diameter of the smallest surrounding cylinder of the first end 21 and the second end 23.

[0034] A first through hole and a second through hole opposite to each other are provided on the front end flow channels 11 and 12 of the turbine housing 1. The first end 21 of the valve rotor 2 passes through the first through hole to connect to the actuating mechanism 3 that drives the valve rotor 2 to rotate around the rotation axis. The cover plate 4 covers the second through hole and forms a receiving groove for receiving the second end 23 of the valve rotor 2.

[0035] The first end portion 21 of the valve rotor 2 is inserted into the first through hole through the second through hole and passes through the first through hole, and then the second through hole is covered with a cover plate 4, thereby realizing the assembly of the valve rotor 2 and the turbine housing 1.

[0036] A sealing ring (not shown) may also be disposed outside the middle portion 21 of the valve rotor 2 to achieve a rotational airtight seal between the valve rotor 2 and the turbine housing 1 .

[0037] refer to Figure 3a and Figure 3b The middle part 22 of the valve rotor 2 is provided with two rotor flow channels, and any rotor flow channel forms a first opening 24 and a second opening 25 on the side surface of the middle part 22. The valve rotor 2 is rotated to control the opening and closing of the intake flange 14 and the bypass flow channel 17, and the ratio of the airflow entering the rear end flow channel 15 and the bypass flow channel 17 to match different application conditions of the engine, wherein the rotor flow channel is connected to the front end flow channels 11 and 12 one by one.

[0038] In other embodiments, the front end flow channel is a single flow channel, and a single rotor flow channel is also provided in the valve rotor 2 .

[0039] Along the extension direction of the flow channel from the intake flange 14 to the vortex tongue 16, the flow channel area of ​​the front end flow channel is reduced linearly or nearly linearly, and the change range of the fluid direction of the front end flow channel is within 30°.

[0040] That is, the trajectories of the front end flow channels 11 and 12 and the areas of the flow channels vary relatively evenly and slowly, which can effectively suppress vortex turbulence.

[0041] Specifically, refer to Figure 4a and Figure 4b The free end of the vortex tongue 16 is rounded, and the turbine housing 1 is used to install the turbine impeller, and at the same time passes through the axis of the turbine impeller ( Figure 4a The plane of the center of the rounded corner section of the free end of the vortex tongue 16 is a first plane F1, the area of ​​the cross section of the front end flow channel 11, 12 perpendicular to its center line L0 and the distance from the center of mass of the cross section to the first plane F1 change linearly or nearly linearly, and the maximum angle between the plane perpendicular to the center line L0 at each position of the center line L0 of the front end flow channel 11, 12 and the first plane F1 is less than 30° (in other words, the angle between the tangent at each position of the center line L0 of the front end flow channel 11, 12 and the tangent of the center line L0 of the front end flow channel at the vortex tongue is less than 30°). Preferably, the angle between the tangent at each position of the center line L0 of the front end flow channel 11, 12 and the tangent of the center line L0 of the front end flow channel at the vortex tongue is less than 10°.

[0042] For example, the angle between the plane where the opening of the air intake flange 14 is located (referred to as the fourth plane F4 in the present disclosure) and the first plane F1 is less than 30°.

[0043] That is, the trajectories of the front end flow channels 11 and 12 and the areas of the flow channels vary relatively evenly and slowly, which can effectively suppress vortex turbulence.

[0044] refer to Figure 4c When the valve rotor 2 rotates to the setting state where the bypass flow channel 17 is closed and the air flow resistance through the valve rotor 2 is the minimum, in order to maximize the effective flow area before and after the air flow passes through the rotor and further reduce the air flow resistance, in the cross section of the rotary turbine bypass valve perpendicular to the turbine impeller axis, the angle between the tangent lines of any rotor flow channel of the valve rotor 2 and the turbine housing 1 at the junction of the two is within the range of 170° to 180°. Preferably, the range of the angle is 175° to 180°.

[0045] When the airflow flows from the front end flow channel 11, 12 into one opening of the valve rotor 2, and flows from the other opening of the valve rotor 2 into the front end flow channel 11, 12, the outer contour of the airflow track is slowly changing, which is also conducive to suppressing vortex turbulence.

[0046] For example Figure 4c The angles A and B are both close to 180°.

[0047] refer to Figure 4cWhen the airflow enters the turbine from the volute, that is, the valve rotor 2 rotates to close the bypass channel 17, in order to maximize the effective flow area before and after the airflow flows through the rotor and minimize the airflow resistance, in the cross section of the rotary turbine bypass valve perpendicular to the axis of the turbine impeller, the distance difference between the rotor channel of the valve rotor 2 and the turbine housing 1 at the junction to the reference straight line F5 is less than 1 mm. The reference straight line F5 is the intersection of the axis of the turbine impeller and the cross section in the cross section, and the extension direction is the average of the extension direction of the center line L0 of the inlet flow channel in the cross section.

[0048] refer to Figure 4b , a plane perpendicular to the center line L0 of the front end flow channels 11, 12, intersecting the middle part 22 of the valve rotor 2 and closest to the vortex tongue 16 is the second plane F2, and the area of ​​the front end flow channels 11, 12 intercepted by the second plane F2 is the second area. When the valve rotor 2 rotates to a state where the bypass flow channel 17 is closed and the airflow resistance of the front end flow channels 11, 12 is minimal, the orthographic projection area of ​​the opening of the rotor flow channel toward the second plane F2 on the second plane F2 is greater than or equal to the second area.

[0049] A plane perpendicular to the center line L0 of the front end flow channels 11, 12, tangent to the middle portion 22 of the valve rotor 2 and farthest from the vortex tongue 16 is the third plane F3. The area of ​​the front end flow channels 11, 12 intercepted by the third plane F3 is the third area. When the valve rotor 2 rotates to a state where the bypass flow channel 17 is closed and the airflow resistance of the front end flow channels 11, 12 is minimal, the orthographic projection area of ​​the opening of the rotor flow channel toward the third plane F3 on the third plane F3 is less than or equal to the third area.

[0050] The areas of the first opening 24 and the second opening 25 are relatively large, which can also effectively reduce the resistance encountered by the airflow when entering and exiting the valve rotor 2 .

[0051] When the number of the front end flow channels 11 and 12 is 2 and the areas of the two are equal (that is, the front end flow channels 11 and 12 are symmetrical flow channels), refer to Figure 3a and Figure 3b , the diameters of the sections in the middle portion 22 of the valve rotor 2 that are opposite to the front end flow passages 11 , 12 are equal.

[0052] When the number of front end flow channels 11, 12 is two and the areas of the two are not equal (ie, the front end flow channels 11, 12 are asymmetric flow channels), the diameter of the section in the middle portion 22 of the valve rotor 2 opposite to the larger front end flow channels 11, 12 is relatively large.

[0053] The diameter of the middle portion 22 of the valve rotor 2 must match the size of the front end flow channels 11, 12, so that the airflow can evenly transition from the front end flow channels 11, 12 to the valve rotor 2, and evenly transition from the valve rotor 2 to the front end flow channels 11, 12, thereby reducing turbulent losses.

[0054] The disclosed embodiment further provides a turbocharger, including the aforementioned rotary turbine bypass valve. The present disclosure does not limit the design of the remaining components of the turbocharger. For example, the turbocharger also includes a turbine impeller installed in the rear end flow channel 15 and a rotating shaft supporting the rotation of the turbine impeller. The turbine impeller and the turbine bypass valve constitute a turbine with an integrated bypass valve and a bypass flow channel 17. Of course, the turbocharger should also include a compressor, and the rotating shaft of the turbine drives the rotating shaft of the compressor to rotate. For another example, an intermediate shell is usually arranged between the turbine housing 1 and the compressor housing 1.

[0055] The various embodiments in the present disclosure are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0056] The protection scope of the present disclosure is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the scope and spirit of the present disclosure. If these changes and modifications fall within the scope of the claims of the present disclosure and their equivalents, the intention of the present disclosure also includes these changes and modifications.

Claims

1. A rotary turbine bypass valve, characterized in that: include: turbine housing, valve rotor and cover plate; The turbine housing includes a main flow channel and a bypass flow channel, the main flow channel includes at least one front flow channel defined by an intake flange and a vortex tongue and a rear flow channel defined by the vortex tongue and an exhaust port of the main flow channel, the bypass flow channel is connected to the main flow channel at the position of the front flow channel, and a valve chamber is formed at the connection between the bypass flow channel and the front flow channel, and the valve rotor is arranged in the valve chamber in a manner that it can rotate freely along a rotation axis; The valve rotor comprises a first end, a middle portion, and a second end which are sequentially arranged along an extension direction of the rotation axis, the smallest enclosing cylinders of the first end, the middle portion, and the second end all have the rotation axis as the axis, the diameter of the smallest enclosing cylinder of the middle portion of the valve rotor is larger than the diameters of the smallest enclosing cylinders of the first end and the second end, the turbine housing is provided with a first through hole and a second through hole which are opposite to each other at a position opposite to the front end flow passage, the first end of the valve rotor passes through the first through hole to be connected to an actuating mechanism which drives the valve rotor to rotate around the rotation axis, the cover plate covers the second through hole and forms a receiving groove for receiving the second end of the valve rotor; The middle part of the valve rotor is provided with at least one rotor flow channel, each of the rotor flow channels is formed with a first opening and a second opening on the side of the middle part, and the proportion of the airflow received by the rear end flow channel and the bypass flow channel is allocated by rotating the valve rotor, wherein the rotor flow channel is connected with the front end flow channel in a one-to-one correspondence; Along the extension direction of the flow channel from the inlet flange to the vortex tongue, the flow channel area of ​​the front end flow channel is linearly reduced or nearly linearly reduced, and the change range of the fluid direction of the front end flow channel is within 30°; The free end of the vortex tongue is chamfered, and the turbine housing is used to place a turbine impeller. The plane passing through the axis of the turbine impeller and the center of the chamfered section of the free end of the vortex tongue is a first plane. The area of ​​the cross-section of the front end flow channel perpendicular to its center line and the distance from the center of mass of the cross-section to the first plane change linearly or nearly linearly, and the angle between the tangent at each position of the center line of the front end flow channel and the tangent of the center line of the front end flow channel at the vortex tongue is less than 30°.

2. The rotary turbine bypass valve according to claim 1, characterized in that: The angle between the tangent line at each position of the center line of the front end flow channel and the tangent line of the center line of the front end flow channel at the vortex tongue is less than 10°.

3. The rotary turbine bypass valve according to claim 1, characterized in that: When the valve rotor rotates to a set state in which the bypass flow channel is closed and the air flow resistance through the valve rotor is minimized, in a cross section of the rotary turbine bypass valve perpendicular to the axis of the turbine impeller, the angle between the tangent lines of the rotor flow channel of the valve rotor and the turbine casing at the junction is in the range of 170° to 180°, and the distance difference between the rotor flow channel of the valve rotor and the turbine casing at the junction to a reference straight line is less than 1 mm, and the reference straight line is a line passing through the intersection of the axis of the turbine casing impeller and the cross section in the cross section and extending in a direction that is the average of the extension direction of the center line of the intake flow channel in the cross section.

4. The rotary turbine bypass valve according to claim 3, characterized in that: When the valve rotor rotates to the set state, in the cross section of the rotary turbine bypass valve perpendicular to the axis of the turbine impeller, the angle between the tangent lines of the rotor flow channel of the valve rotor and the turbine casing at the junction is in the range of 175° to 180°.

5. The rotary turbine bypass valve according to claim 3, characterized in that: In the set state, a plane that is perpendicular to the center line of the front section of the flow channel, intersects the middle part of the valve rotor and is closest to the vortex tongue is a second plane, the area of ​​the main flow channel intercepted by the second plane is a second area, and the orthographic projection area of ​​the opening of the rotor flow channel toward the second plane on the second plane is greater than or equal to the second area. A plane that is perpendicular to the center line of the front section of the flow channel, intersects the middle part of the valve rotor and is farthest from the vortex tongue is a third plane, the area of ​​the main flow channel intercepted by the third plane is a third area, and the orthographic projection area of ​​the opening of the rotor flow channel toward the third plane on the third plane is less than or equal to the third area.

6. A turbocharger, characterized in that: It comprises a turbine bypass valve according to any one of claims 1 to 5.

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