Double scroll turbine and turbocharger
The double-scroll turbine addresses inefficiencies in existing designs by using separate opening/closing plates for communication and bypass paths, enabling flexible control and reducing leakage, thus improving efficiency and simplifying the turbine housing.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- MITSUBISHI HEAVY IND ENGINE & TURBOCHARGER LTD
- Filing Date
- 2023-03-31
- Publication Date
- 2026-07-22
AI Technical Summary
Existing double scroll turbines face challenges in freely opening and closing communication and bypass flow paths due to the use of a single valve body, leading to inefficiencies such as unintended flow through the bypass path when the communication path is opened, and partial opening of the communication path when both paths should be closed.
A double-scroll turbine design with separate first and second opening/closing plates on a valve stem to independently control the communication and bypass flow paths, allowing for flexible timing and synchronization of their openings and closings, and a configuration that separates the valve device from the turbine housing to simplify the design.
Enables independent and flexible control of the communication and bypass flow paths, reducing unintended gas leakage and enhancing turbine efficiency by allowing precise timing adjustments and simplifying the turbine housing configuration.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a double scroll turbine in which two scroll flow paths are formed, and a turbocharger.
Background Art
[0002] Conventionally, a double scroll turbine in which a communication flow path for communicating two scroll flow paths and a bypass flow path connected to the communication flow path and an exhaust gas flow path are formed is known. For example, the double scroll turbine disclosed in Patent Document 1 includes a flap valve for opening and closing the communication flow path and the bypass flow path.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the double scroll turbine of Patent Document 1, since a single valve body is used to open and close the communication flow path and the bypass flow path, there is a risk that it may be difficult to freely open and close these two flow paths. To give a specific example, when the valve body opens the communication flow path, there is a risk that the bypass flow path will also be inevitably opened. Therefore, when the valve is opened to allow exhaust gas to flow through the communication flow path, exhaust gas also flows through the bypass flow path, resulting in a decrease in turbine efficiency. Another example is that even when the valve body is arranged at a position where the communication flow path and the bypass flow path are closed, there is a risk that the communication flow path will be slightly opened.
[0005] An object of the present disclosure is to provide a double scroll turbine and a turbocharger that can freely open and close a communication flow path and a bypass flow path.
Means for Solving the Problems
[0006] A double scroll turbine according to at least one embodiment of the present disclosure is A double-scroll turbine comprising a turbine housing formed with two double-scroll type scroll passages configured to guide exhaust gas to a turbine wheel, and a discharge passage for discharging the exhaust gas that has passed through the turbine wheel, The turbine housing is A communication channel wall defines a communication channel that connects the two scroll channels to each other, A bypass channel wall defines a bypass channel for guiding the exhaust gas flowing through the aforementioned communication channel to the discharge channel, bypassing the turbine wheel, and Includes, The wall of the communication channel is provided with an outlet that guides the exhaust gas flowing through the communication channel to the bypass channel. The aforementioned double-scroll turbine further comprises a valve device, The valve device is A valve stem extending across the aforementioned communication channel, wherein the valve stem is provided such that its axis passes through the aforementioned outlet, A first opening / closing plate attached to the valve stem so as to extend along the axis, the first opening / closing plate for opening and closing the communication passage in conjunction with the rotation of the valve stem, A second opening / closing plate extends in a direction intersecting the aforementioned axis and is attached to the valve stem on the outlet side of the first opening / closing plate, and the second opening / closing plate is for opening and closing the bypass passage in accordance with the rotation of the valve stem. Includes.
[0007] A turbocharger according to at least one embodiment of this disclosure is The axis of rotation and The double scroll turbine includes the turbine wheel connected to one end of the rotating shaft, A compressor including a compressor wheel connected to the other end of the aforementioned rotating shaft It is equipped with. [Effects of the Invention]
[0008] According to the present disclosure, a double-scroll turbine capable of freely opening and closing a communication flow path and a bypass flow path, and a turbocharger can be provided.
Brief Description of the Drawings
[0009] [Figure 1] It is a schematic diagram of a turbocharger according to an embodiment. [Figure 2] It is a schematic diagram of a turbine according to an embodiment. [Figure 3] It is a schematic diagram of a turbine housing according to an embodiment. [Figure 4] It is a schematic diagram of a valve device according to an embodiment. [Figure 5] It is a schematic diagram of an opposing plate according to an embodiment. [[ID=?]] [Figure 6] It is a schematic diagram of a second opening / closing plate according to an embodiment. [Figure 7A] It is a schematic diagram showing the opening process of a communication flow path according to an embodiment. [Figure 7B] It is a schematic diagram showing the opening process of the communication flow path following FIG. 7A. [Figure 7C] It is a schematic diagram showing the opening process of the communication flow path following FIG. 7B. [Figure 7D] It is a schematic diagram showing the opening process of the communication flow path following FIG. 7C. [Figure 8A] It is a schematic diagram showing the opening process of a passage port according to an embodiment. [Figure 8B] It is a schematic diagram showing the opening process of the passage port following FIG. 8A. [Figure 8C] It is a schematic diagram showing the opening process of the passage port following FIG. 8B. [Figure 8D] It is a schematic diagram showing the opening process of the passage port following FIG. 8C.
Mode for Carrying Out the Invention
[0010] Note: There seems to be a missing ID number in the original text where it says " [Figure 6] ". It's translated as-is in the above content.Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, but are merely illustrative examples. For example, expressions representing relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" not only strictly represent such arrangements, but also represent a state in which there are tolerances or relative displacements with angles and distances that can achieve the same function. For example, expressions representing that things such as "identical", "equal", and "homogeneous" are in an equal state not only strictly represent an equal state, but also represent a state in which there are tolerances or differences that can achieve the same function. For example, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent shapes such as a rectangular shape or a cylindrical shape in a geometrically strict sense, but also represent shapes including concave and convex portions, chamfered portions, etc. within a range where the same effect can be obtained. On the other hand, the expressions "comprising", "including", or "having" for one component are not exclusive expressions that exclude the existence of other components. Note that the same reference numerals may be given to the same configurations and the description may be omitted.
[0011] <Overall Configuration of Turbocharger 1> FIG. 1 is a schematic diagram showing a turbocharger 1 according to an embodiment of the present disclosure. The turbocharger 1 in this example is mounted on an engine 12 that may be applied to, for example, an automobile. The turbocharger 1 includes a double-scroll turbine 5 including a rotating shaft 3 and a turbine wheel 9 connected to one end 3A of the rotating shaft 3, and a compressor 8 including a compressor wheel 6 connected to the other end 3B of the rotating shaft 3.
[0012] In the following explanation, the double-scroll turbine 5 may sometimes be simply referred to as "turbine 5". Furthermore, the direction in which the central axis C of the rotating shaft 3 extends may be called the "turbine axis direction," and the radial and circumferential directions relative to the central axis C may be called the "turbine radial direction" and "turbine circumferential direction," respectively. The outer side of the turbine radial direction is the direction away from the central axis C, and the inner side of the turbine radial direction is the direction approaching the central axis C.
[0013] The compressor 8 further includes a compressor housing 7 that houses a compressor wheel 6. Air taken in through an intake port 101 formed in the compressor housing 7 is compressed by the compressor wheel 6 and sent to the engine 12. The turbine 5 further includes a double-scroll type turbine housing 10 that houses a turbine wheel 9. The turbine wheel 9 rotates together with the rotating shaft 3 using exhaust gas discharged from the engine 12 as the working fluid. The exhaust gas that has passed through the turbine wheel 9 is discharged through an exhaust port 102 formed in the turbine housing 10.
[0014] <Turbine housing 10> Figure 2 is a schematic diagram of a turbine 5 according to one embodiment of the present disclosure. The turbine housing 10 has two scroll passages 11 for guiding exhaust gas to the turbine wheel 9. The two scroll passages 11 are arranged in the same range relative to each other in the turbine axial direction and are configured to supply exhaust gas to the turbine wheel 9 in different ranges relative to each other in the turbine circumferential direction. The turbine housing 10 also has an exhaust passage 19 (see Figure 1) for discharging the exhaust gas that has passed through the turbine wheel 9 to the outside of the system. In this example, the exhaust passage 19 extends along the turbine axial direction and the exhaust gas that has passed through the turbine wheel 9 is discharged from the exhaust port 102 via the exhaust passage 19.
[0015] Figure 3 is a schematic diagram of a turbine housing 10 according to one embodiment of the present disclosure, and the turbine wheel 9 is schematically shown. The turbine housing 10 includes a communication passage wall 28 that defines a communication passage 18 that connects two scroll passages 11 to each other, and a bypass passage wall 25 that defines a bypass passage 15 that guides exhaust gas flowing through the communication passage 18 to the discharge passage 19, bypassing the turbine wheel 9.
[0016] Both ends of the communication channel wall 28 are connected to communication ports 11A (see Figure 2) formed in the two scroll channels 11. An outlet 41 is also formed in the communication channel wall 28 to guide the exhaust gas flowing through the communication channel 18 to the bypass channel 15. The outlet 41 is located between the two communication ports 11A and is positioned on the discharge channel 19 side of the turbine wheel 9. In this example, the outlet 41 penetrates the communication channel wall 28 along the turbine radial direction.
[0017] <Valve device 30> As shown in Figure 3, the turbine 5 further includes a valve device 30 configured to open and close the communication channel 18 and the bypass channel 15, respectively. The valve device 30 includes a valve stem 35 extending across the communication channel 18, a first opening / closing plate 31 attached to the valve stem 35, and a second opening / closing plate 32 attached to the valve stem 35 on the outlet 41 side of the first opening / closing plate 31. Both the first opening / closing plate 31 and the second opening / closing plate 32 are configured to rotate integrally with the valve stem 35.
[0018] The valve stem 35 in this example has a first end 351 located on the opposite side of the outlet 41 from the communication passage 18, a second end 352 located on the outlet 41 side of the communication passage 18, and an extended portion 353 extending between the first end 351 and the second end 352. Both the first end 351 and the second end 352 are located outside the communication passage wall 28. The axis S of the valve stem 35 configured in this way is substantially perpendicular to the communication passage centerline 18A, which is the centerline of the communication passage 18, and passes through the communication passage 18 and the outlet 41.
[0019] The first opening / closing plate 31, which is attached to the extended portion 353 of the valve stem 35, extends along the axis S. The first opening / closing plate 31 is configured to open and close the communication passage 18 as the valve stem 35 rotates. More specifically, the first opening / closing plate 31 is configured to rotate between a first closed position (see Figure 7A) in which it extends perpendicular to the communication passage centerline 18A and closes the communication passage 18, and a first open position (see Figure 7D) in which it extends parallel to the communication passage centerline 18A and opens the communication passage 18. In the first closed position, the first opening / closing plate 31 completely closes the communication passage 18, and in the first open position, it completely opens the communication passage 18.
[0020] As shown in Figure 3, the second opening / closing plate 32, which is attached to the second end 352 of the valve stem 35, extends so as to intersect the axis S and is formed separately from the first opening / closing plate 31. The second opening / closing plate 32 is configured to open and close the bypass passage 15 in accordance with the rotation of the valve stem 35. More specifically, the second opening / closing plate 32 is configured to switch between a closed state that closes the bypass passage 15 (see Figures 8A and 8B) and an open state that opens the bypass passage 15 (see Figures 8C and 8D). Details of how the second opening / closing plate 32 opens and closes the bypass passage 15 will be described later. In this example, the second opening / closing plate 32 extends so as to be substantially perpendicular to the axis S.
[0021] Since the first opening / closing plate 31 and the second opening / closing plate 32 for opening and closing the communication passage 18 and the bypass passage 15, respectively, are configured separately, a turbine 5 is realized that can freely open and close the communication passage 18 and the bypass passage 15. In this embodiment, it is possible to freely adjust whether or not to open and close the bypass passage 15 at the same time as opening the communication passage 18 during the design phase of the turbine 5. Furthermore, it is possible to shift the opening timing of the bypass passage 15 from the opening timing of the communication passage 18, thereby suppressing unintended leakage of exhaust gas in the bypass passage 15 or the communication passage 18.
[0022] In the following explanation, the axial direction of the axis S of the valve stem 35 may be simply referred to as the "axial direction." Similarly, the radial and circumferential directions relative to the axis S may be simply referred to as the "radial direction" and the "circumferential direction," respectively.
[0023] <Opening and closing structure of bypass channel 15> Figure 4 is a schematic diagram of a valve device 30 according to one embodiment of the present disclosure, Figure 5 is a schematic diagram of an opposing plate 33 according to one embodiment of the present disclosure, and Figure 6 is a schematic diagram of a second opening / closing plate 32 according to one embodiment of the present disclosure.
[0024] As shown in Figures 4 and 5, the turbine 5 further includes an opposing plate 33 that faces the second opening / closing plate 32 from the upstream side in the flow direction of the bypass flow path 15. The circularly shaped opposing plate 33 is constructed separately from the turbine housing 10 and is fixed to the inner surface of the turbine housing 10, for example, by welding. As a more specific example, the outer circumferential surface 339 of the opposing plate 33 is fixed to the inner surface of the communication flow path wall 28 that defines the outlet 41.
[0025] Furthermore, the opposing plate 33 defines a passage 36 for exhaust gas to pass through. The passage 36 is an open hole in the axial direction. In the example of Figure 5, a pair of passage 36 are formed as openings in the opposing plate 33. More specifically, the opposing plate 33 includes a pair of main body portions 39 and a pair of connecting portions 34. Each of the pair of main body portions 39, formed symmetrically with respect to the axis S, has a sector shape with respect to the axis S. The connecting portion 34 extends in the circumferential direction and is connected to the radial outer ends of the pair of main body portions 39. In this configuration, the passage 36 is defined by the circumferential end face 391 of the main body portion 39 and the inner circumferential surface 341 of the connecting portion 34. In this example, the pair of passage 36 are arranged at equal intervals in the circumferential direction. Each passage 36 has a sector shape centered on the axis S. A valve stem 35 is inserted through a central hole formed in the center of the opposing plate 33. In other examples, a single through-hole 36 may be formed in the opposing plate 33 (not shown).
[0026] As shown in Figure 6, the second opening / closing plate 32 has an outer peripheral surface 27 facing radially outward. In this example, the outer peripheral surface 27 extends parallel to the circumferential direction, and the second opening / closing plate 32 exhibits a sector shape centered on the axis S. The diameter of the outer peripheral surface 27 is larger than the diameter of the inner peripheral surface 341 of the opposing plate 33. In the same figure, the maximum distance from the axis S of the valve stem 35 to the outer peripheral surface 27 is denoted as dimension L1. The second opening / closing plate 32 defines an opening 29. The opening 29 is located in the inner region R1 of a first virtual circle 91 centered on the axis S and with radius dimension L1. In the example of Figure 6, the opening 29 is defined by the end face 321 of the second opening / closing plate 32 in the circumferential direction; in other words, multiple second opening / closing plates 32 are arranged in the circumferential direction with an opening 29 between them. In this example, a pair of second opening / closing plates 32 are arranged, and a pair of openings 29 are arranged at equal intervals in the circumferential direction. Furthermore, in the examples shown in Figures 5 and 6, the central angle (θ1) of the sector-shaped second opening / closing plate 32 is greater than the central angle (θ2) of the sector-shaped passage opening 36. In other examples, an opening 29 may be formed as a through hole in a single second opening / closing plate 32 (not shown). In this case, the opening 29 is defined by the opening formed in the second opening / closing plate 32. Also, the number of openings 29 does not have to be the same as the number of through openings 36, and the numbers of the two may be different from each other.
[0027] In this example, the second opening / closing plate 32 is configured to open and close the bypass flow path 15 by opening and closing the passage opening 36. The second opening / closing plate 32 is configured to rotate between a second closed position, which is one end of the movable range (see Figure 8A), and a second open position, which is the other end of the movable range (see Figure 8D). When the second opening / closing plate 32 is in the second closed position, the passage opening 36 is closed by the second opening / closing plate 32, and the opening 29 is positioned circumferentially offset from the passage opening 36. For a while after the second opening / closing plate 32 begins to rotate from the second closed position toward the second open position, the passage opening 36 remains closed by the second opening / closing plate 32 (see Figure 8B). Eventually, the opening 29 comes into axial opposition with a part of the passage opening 36 (see Figure 8C), and when the second opening / closing plate 32 reaches the second open position, the passage opening 36 is fully opened (see Figure 8D).
[0028] According to the above configuration, the position of the opening 29 defined by the second opening / closing plate 32 changes with the rotation of the valve stem 35, thereby enabling the second opening / closing plate 32 to open and close the bypass passage 15. Whether the timing of opening and closing the communication passage 18 and the timing of opening and closing the bypass passage 15 are synchronized or different can be freely adjusted according to the shape of the second opening / closing plate 32, which is determined during the design phase of the turbine 5. This allows for even more flexible opening and closing of the communication passage 18 and the bypass passage 15.
[0029] Furthermore, by providing a separate opposing plate 33 from the turbine housing 10, it becomes possible to avoid complicating the shape of the turbine housing 10. In addition, since the bypass flow path 15 can be opened and closed simply by whether or not the opening 29 defined by the second opening / closing plate 32 faces the passage opening 36, the configuration of the valve device 30 can be simplified.
[0030] Furthermore, with a configuration in which multiple passage ports 36 are arranged, the locations through which exhaust gas passes on the opposing plate 33 can be dispersed, and excessive temperature rise in specific parts of the opposing plate 33 can be suppressed. These technical advantages can also be obtained in embodiments in which multiple passage ports 36 are arranged circumferentially at unequal intervals.
[0031] Furthermore, with a configuration in which multiple openings 29 are arranged circumferentially at the same number as multiple passage openings 36, the amount of rotation of the second opening / closing plate 32 required to open and close the bypass flow path 15 can be reduced compared to the case where the number of openings 29 is less than the number of passage openings 36. This allows the bypass flow path 15 to be opened and closed quickly.
[0032] <Opening and closing timing of the connecting channel 18 and the bypass channel 15> The opening and closing timings of the communication channel 18 and the bypass channel 15 will be explained with reference to Figures 7A to 7D and Figures 8A to 8D. Figures 7A to 7D are schematic diagrams showing the opening process of the communication channel 18 according to one embodiment of the present disclosure, and Figures 8A to 8D are schematic diagrams showing the opening process of the passage opening 36 according to one embodiment of the present disclosure. Figures 7A and 8A show the state of the valve device 30 at the same time, and Figures 7B and 8B show the state of the valve device 30 at the same time. The same relationship holds between Figure 7C and Figure 8C, and between Figure 7D and Figure 8D. Note that in Figures 8A to 8D, for the sake of clarity, the radius of the second opening / closing plate 32 is shown to be larger than the radius of the opposing plate 33, but the second opening / closing plate 32 and the opposing plate 33 may have the same radius.
[0033] As shown in Figures 7A and 7B, as the valve stem 35 rotates, the first opening plate 31 rotates from the first open position and begins to open the communication passage 18. At this time, as shown in Figures 8A and 8B, the second opening plate 32 also rotates from the second open position to the second closed position, but because the central angle of the second opening plate 32 is larger than the central angle of the passage opening 36, the opening 29 remains shifted circumferentially from the passage opening 36. In other words, the second opening plate 32 maintains a closed state. As shown in Figures 7B and 7C, the first opening / closing plate 31 rotates further, opening the communication channel 18 even more. In other words, the degree of opening of the communication channel 18 gradually increases. At this time, as shown in Figures 8B and 8C, the opening 29 comes into axial contact with a part of the passage opening 36, and the second opening / closing plate 32 switches from the closed state to the open state. As shown in Figures 7C and 7D, when the first opening / closing plate 31 rotates further and reaches the first open position, the communication channel 18 is fully opened. At this time, as shown in Figures 8C and 8D, as the second opening / closing plate 32 rotates toward the second open position, the opening of the passage opening 36 gradually increases. In other words, the opening of the bypass channel 15 gradually increases. When the second opening / closing plate 32 reaches the second open position, the opening 29 faces the entire passage opening 36 in the axial direction, and the second opening / closing plate 32 fully opens the passage opening 36. In other words, the bypass channel 15 is fully opened.
[0034] With the above configuration, even when the first opening / closing plate 31 slightly opens the communication channel 18 (see Figure 7B), the second opening / closing plate 32 can maintain a closed state (see Figure 8B). Also, at the same time that the first opening / closing plate 31 fully opens the communication channel 18 (see Figure 7D), the second opening / closing plate 32 can also fully open the bypass channel 15 (see Figure 8D).
[0035] <Extending direction of valve stem 35> Returning to Figure 3, in some embodiments of this disclosure, when viewed along the turbine axis, the axis S of the valve stem 35 passes through the inner region R2 of the second virtual circle 92. Here, the second virtual circle 92 is a virtual circle with a central axis C and a diameter less than or equal to the outer diameter (diameter) of the turbine wheel 9. The diameter of the second virtual circle 92 may be, for example, 10% or more and 75% or less, or 10% or more and 50% or less, relative to the outer diameter of the turbine wheel 9. It may be 10% or more and 25% or less. In this example, the axis S passes through the central axis C when viewed along the turbine axis direction. When such a configuration is adopted, the two communication ports 11A (see Figure 2) that connect to both ends of the communication channel 18 will be positioned at different locations in the turbine radial direction.
[0036] According to the above configuration, when viewed along the turbine axis, the outlet 41 directs the exhaust gas toward the central axis C of the turbine wheel 9, thus shortening the length of the bypass passage 15 that guides the exhaust gas to the discharge passage 19. Therefore, the configuration of the turbine housing 10 can be simplified.
[0037] <Drive unit of valve device 30> Returning to Figure 1, the valve device 30 further includes an actuator 37 for driving the valve stem 35 and a connecting rod 38 connecting the actuator 37 to the first end 351 (see Figure 3) of the valve stem 35. The actuator 37 is fixed to the compressor housing 7. The connecting rod 38 extends along the turbine axis and is configured to transmit the driving force of the actuator 37 to the valve stem 35. As the valve stem 35 rotates in conjunction with the driving of the actuator 37, the valve device 30 can open and close the communication passage 18 and the bypass passage 15, respectively.
[0038] With the above configuration, the actuator 37 is located in the compressor housing 7 rather than the turbine housing 10, which tends to get relatively hot, thus preventing a temperature rise in the actuator 37 and the connecting rod 38. This prevents thermal deformation of the valve stem 35, and thus prevents the axis S of the valve stem 35 from shifting from the desired position.
[0039] <Summary> The contents described in some of the embodiments above can be understood, for example, as follows:
[0040] 1) A double scroll turbine (5) according to at least one embodiment of the present disclosure is A double-scroll turbine comprising a turbine housing (10) having two double-scroll type scroll passages (11) configured to guide exhaust gas to a turbine wheel (9), and an exhaust passage (19) for discharging the exhaust gas that has passed through the turbine wheel, The turbine housing is A communication channel wall (28) defines a communication channel (18) that connects the two scroll channels to each other, A bypass passage wall (25) defines a bypass passage (15) for guiding the exhaust gas flowing through the aforementioned communication passage to the discharge passage, bypassing the turbine wheel, and Includes, The wall of the communication channel has an outlet (41) formed therein that guides the exhaust gas flowing through the communication channel to the bypass channel. The aforementioned double-scroll turbine further comprises a valve device (30), The valve device is A valve stem (35) extending across the aforementioned communication channel, wherein the axis (S) is provided to pass through the outlet, A first opening / closing plate (31) attached to the valve stem so as to extend along the axis, for opening and closing the communication passage in accordance with the rotation of the valve stem, A second opening / closing plate (32) extends in a direction intersecting the axis and is attached to the valve stem on the outlet side of the first opening / closing plate, and opens and closes the bypass passage in accordance with the rotation of the valve stem. Includes.
[0041] According to the configuration described in 1) above, the first and second opening / closing plates for opening and closing the connecting channel and the bypass channel, respectively, are configured separately from each other, thereby realizing a double-scroll turbine with improved freedom of opening and closing of the connecting channel and the bypass channel. In such a double-scroll turbine, it is possible to freely adjust whether or not to open and close the bypass channel at the same time as opening the connecting channel during the design phase of the double-scroll turbine. Furthermore, it becomes possible to shift the opening timing of the bypass channel from the opening timing of the connecting channel, thereby suppressing unintended leakage of exhaust gas in the bypass channel or the connecting channel.
[0042] 2) In some embodiments, the double scroll turbine described in 1) above, The second opening / closing plate defines an opening (29) located in the inner region (R1) of a first virtual circle (91) centered on the axis and with a radius equal to the maximum distance from the axis to the outer surface (27) of the second opening / closing plate. The second opening / closing plate is configured to switch between an open state, which connects the communication channel and the bypass channel through the opening, and a closed state, which closes the bypass channel, as the valve stem rotates.
[0043] According to the configuration described in 2) above, the position of the opening defined by the second opening / closing plate changes with the rotation of the valve stem, allowing the second opening / closing plate to open and close the bypass passage. Whether the timing of opening and closing the communication passage and the timing of opening and closing the bypass passage are synchronized or different can be freely adjusted according to the shape of the second opening / closing plate, which is determined during the design phase of the double scroll turbine. This allows for even more flexible opening and closing of the communication passage and the bypass passage.
[0044] 3) In some embodiments, the double scroll turbine described in 2) above, An opposing plate facing the second opening / closing plate from the upstream side in the flow direction of the bypass flow path, further comprising an opposing plate (33) that defines a passage opening (36) for the exhaust gas to pass through, The second opening / closing plate is configured to open the bypass passage by facing the passage opening, and to close the bypass passage by shifting the opening away from the passage opening. The double-scroll turbine according to claim 2.
[0045] According to the configuration described in 3) above, a separate opposing plate is provided from the turbine housing, which makes it possible to avoid complicating the shape of the turbine housing. In addition, since the bypass flow path can be opened and closed simply by whether the opening defined by the second opening / closing plate faces the passage opening or not, the configuration of the valve device can be simplified.
[0046] 4) In some embodiments, the double scroll turbine described in 3) above, Multiple passage openings are arranged at intervals in the circumferential direction with respect to the axis.
[0047] According to the configuration described in 4) above, since multiple passage openings are arranged, the locations through which exhaust gas passes on the opposing plate can be distributed, and excessive temperature rise in specific parts of the opposing plate can be suppressed.
[0048] 5) In some embodiments, the double scroll turbine described in 4) above, The plurality of passage openings are arranged at equal intervals in the circumferential direction, The openings defined by the second opening / closing plate are spaced apart in the circumferential direction and arranged at equal intervals in the same number as the plurality of passage openings.
[0049] According to the configuration described in 5) above, the amount of rotation of the second opening / closing plate required to open and close the bypass channel can be reduced compared to the case where the number of openings is less than the number of passage ports. This allows the bypass channel to be opened and closed quickly.
[0050] 6) In some embodiments, a double scroll turbine according to any one of 1) to 5) above, When viewed along the axial direction of the turbine wheel (turbine axis direction), the axis of the valve stem passes through the inner region (R2) of a second virtual circle (92) whose diameter is less than or equal to the outer diameter of the turbine wheel, with the diameter centered on the central axis (C) of the turbine wheel.
[0051] According to the configuration described in 6) above, when viewed along the axial direction, the outlet directs the exhaust gas toward the central axis of the turbine wheel, thus shortening the length of the bypass passage. Therefore, the configuration of the turbine housing can be simplified.
[0052] 7) A turbocharger (1) according to at least one embodiment of the present disclosure is Rotation axis (3) and, A double scroll turbine (5) according to any one of items 1) to 5) above, including the turbine wheel (9) connected to one end (3A) of the rotating shaft, A compressor (8) including a compressor wheel (6) connected to the other end (3B) of the rotating shaft and It is equipped with.
[0053] According to the configuration in 7) above, the same technical advantages as in 1) above can be obtained.
[0054] 8) In some embodiments, the double scroll turbine described in 7) above, The compressor further includes a compressor housing (7) that houses the compressor wheel, The valve device is An actuator (37) for driving the valve stem, A connecting rod (38) connected to the actuator and the valve stem, configured to transmit the driving force of the actuator to the valve stem, It further includes, The actuator is positioned in the compressor housing.
[0055] According to the configuration described in 8) above, the actuator is located in the compressor housing rather than the turbine housing, which tends to get relatively hot, thus preventing temperature increases in the actuator and connecting rod. This prevents thermal deformation of the valve stem 35, and thus prevents the valve stem axis from shifting from the desired position. [Explanation of Symbols]
[0056] 1: Turbocharger 3: Rotation axis 3A: One end 3B:Other end 5: Double-scroll turbine (turbine) 6: Compressor Wheel 7: Compressor Housing 8: Compressor 9: Turbine Wheel 10: Turbine Housing 11: Scroll channel 15: Bypass channel 18: Connecting channel 18A: Centerline of the connecting channel 19: Discharge channel 25: Bypass channel wall 27: Outer surface 28: Connecting channel wall 29 :Aperture 30: Valve device 31: First opening / closing plate 32: Second opening / closing plate 33: Opposing plate 34:Connection part 35: Valve stem 36: Passage gate 37: Actuator 38: Connecting rod 39: Main body 41: Outlet 91: First Virtual Yen 92: Second Virtual Yen 339: Outer surface 351: First end 352 :Second end 353 :Extension part C: Center axis L1: Dimensions R1,R2: Inner area
Claims
1. A double-scroll turbine comprising a turbine housing having two double-scroll type scroll passages configured to guide exhaust gas to a turbine wheel, and a discharge passage for discharging the exhaust gas that has passed through the turbine wheel, The turbine housing is A communication channel wall defines a communication channel that connects the two scroll channels to each other, A bypass channel wall defines a bypass channel for guiding the exhaust gas flowing through the aforementioned communication channel to the discharge channel, bypassing the turbine wheel, and Includes, The wall of the communication channel is provided with an outlet that guides the exhaust gas flowing through the communication channel to the bypass channel. The aforementioned double-scroll turbine further comprises a valve device, The valve device is A valve stem extending across the aforementioned communication channel, wherein the valve stem is provided such that its axis passes through the aforementioned outlet, A first opening / closing plate attached to the valve stem so as to extend along the axis, the first opening / closing plate for opening and closing the communication passage in conjunction with the rotation of the valve stem, A second opening / closing plate extends in a direction intersecting the aforementioned axis and is attached to the valve stem on the outlet side of the first opening / closing plate, and the second opening / closing plate is for opening and closing the bypass passage in accordance with the rotation of the valve stem. including Double scroll turbine.
2. The second opening / closing plate defines an opening located in the inner region of a first virtual circle centered on the axis and with a radius equal to the maximum distance from the axis to the outer surface of the second opening / closing plate. The second opening / closing plate is configured to switch between an open state, which connects the communication channel and the bypass channel through the opening, and a closed state, which closes the bypass channel, as the valve stem rotates. The double-scroll turbine according to claim 1.
3. The bypass flow path comprises an opposing plate facing the second opening / closing plate from the upstream side in the flow direction, which further defines an opening for the exhaust gas to pass through. The second opening / closing plate is configured to open the bypass passage by facing the passage opening, and to close the bypass passage by shifting the opening away from the passage opening. The double-scroll turbine according to claim 2.
4. Multiple passage openings are arranged at intervals in the circumferential direction with respect to the axis. The double-scroll turbine according to claim 3.
5. The plurality of passage openings are arranged at equal intervals in the circumferential direction, The openings defined by the second opening / closing plate are spaced apart in the circumferential direction and arranged at equal intervals, in the same number as the plurality of passage openings. The double-scroll turbine according to claim 4.
6. When viewed along the axial direction of the turbine wheel, the axis of the valve stem passes through the inner region of a second virtual circle whose diameter is less than or equal to the outer diameter of the turbine wheel, with the diameter centered on the central axis of the turbine wheel. A double-scroll turbine according to any one of claims 1 to 3.
7. The axis of rotation and A double scroll turbine according to any one of claims 1 to 3, including the turbine wheel connected to one end of the rotating shaft, A compressor including a compressor wheel connected to the other end of the aforementioned rotating shaft A turbocharger equipped with [a specific feature].
8. The compressor further includes a compressor housing that accommodates the compressor wheel, The valve device is An actuator for driving the valve stem, A connecting rod connected to the actuator and the valve stem, configured to transmit the driving force of the actuator to the valve stem, It further includes, The actuator is located in the compressor housing. The turbocharger according to claim 7.