Turbine housing, turbine and turbocharger

Abstract

The present invention provides a turbine housing comprising at least a scroll connection valve including a valve plug having at least a head portion and a seat portion, the head portion being capable of dividing two branching channels, each branching respectively from two scroll channels, by abutting a branching wall dividing the two branching channels individually in a common channel in which the two branching channels meet and which communicates, via a communicating port, with an exhaust channel in which exhaust gas that has passed through a turbine wheel flows, the seat portion extending peripherally outward past the head portion and being capable of closing off the communicating port by abutting a seat wall surface of the turbine housing, wherein the seat portion has a deformation allowance to allow the head portion to abut the branching wall after the seat portion abuts the seat wall surface during closing operation of the scroll connection valve.

Description

[Technical Field]

[0001] The present disclosure relates to a turbine housing, a turbine including the turbine housing, and a turbocharger. [Background technology]

[0002] Some turbine housings are formed with a first branch passage branching from a first scroll passage, a second branch passage branching from a second scroll passage, and a confluence passage where the first branch passage and the second branch passage join and which communicates with an exhaust passage through which exhaust gas that has passed through the turbine wheel flows (see Patent Document 1).The turbine housing described in Patent Document 1 discloses a valve that can close a communication port provided between the confluence passage and the exhaust passage and has a valve body that can separate the first branch passage and the second branch passage in the confluence passage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2018-537615 Summary of the Invention [Problem to be solved by the invention]

[0004] If one attempts to simultaneously seal the gap between the two branch passages in the converging passage and the gap between the converging passage and the exhaust passage, the turbine housing structure becomes complicated. Also, if the turbine housing structure is simplified, it becomes difficult to simultaneously seal the gap between the two branch passages in the converging passage and the gap between the converging passage and the exhaust passage.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a turbine housing, a turbine, and a turbocharger that has a simple turbine housing structure and is capable of simultaneously sealing between two branch passages in a confluent passage and sealing between the confluent passage and an exhaust passage. [Means for solving the problem]

[0006] A turbine housing according to at least one embodiment of the present disclosure includes: A turbine housing in which two scroll passages are formed, a scroll passage forming portion that forms the two scroll passages; a connecting passage forming section that forms connecting passages including a first branch passage branching from one of the two scroll passages, a second branch passage branching from the other of the two scroll passages, and a confluence passage where the first branch passage and the second branch passage merge and that communicates via a communication port with an exhaust passage through which exhaust gas that has passed through a turbine wheel flows, the connecting passage forming section having a branch wall that separates the first branch passage and the second branch passage; a turbine housing body including: a head portion that can separate the two branch flow paths by contacting the branch wall in the joining flow path; a seat portion extending radially outward of the valve body beyond the head portion, the seat portion being capable of closing the communication port by abutting against a seat wall surface of the turbine housing. a scroll connection valve including: The seat portion has a deformation allowance for allowing the head portion to abut against the branch wall after the seat portion abuts against the seat wall surface during a closing operation of the scroll connection valve.

[0007] A turbine according to at least one embodiment of the present disclosure comprises: the turbine housing; a turbine wheel rotatably housed in the turbine housing.

[0008] A supercharger according to at least one embodiment of the present disclosure includes: a turbine driven by exhaust gas discharged from an engine, the turbine; a compressor that is coaxially connected to the turbine and that supplies compressed air to the engine as the turbine rotates. [Effects of the Invention]

[0009] According to at least one embodiment of the present disclosure, a turbine housing, a turbine, and a turbocharger are provided that have a simple turbine housing structure and are capable of simultaneously sealing between two branch passages in a confluent passage and sealing between the confluent passage and the exhaust passage. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an engine system including a supercharger according to an embodiment; [Figure 2] FIG. 2 is a schematic cross-sectional view of a scroll connection valve of a turbine housing according to an embodiment of the present invention, taken along an axis line of the valve. [Figure 3] 2 is a schematic cross-sectional view of the turbine housing according to the first embodiment, taken along the axis of the scroll connection valve when the scroll connection valve is in a fully closed state. FIG. [Figure 4] 2 is a schematic cross-sectional view of the turbine housing according to the first embodiment, taken along the axis of the scroll connection valve when the scroll connection valve is in a fully open state. FIG. [Figure 5] FIG. 10 is a schematic cross-sectional view of a turbine housing according to a modified example of the first embodiment, taken along the axis of a scroll connection valve when the scroll connection valve is in a fully open state. [Figure 6] FIG. 10 is a schematic cross-sectional view of a turbine housing according to a second embodiment, taken along the axis of a scroll connection valve when the scroll connection valve is in a fully closed state. [Figure 7]FIG. 10 is a schematic cross-sectional view of a turbine housing according to a third embodiment, taken along the axis of a scroll connection valve when the scroll connection valve is in a fully closed state. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure.

[0012] (Turbocharger) FIG. 1 is a schematic diagram of an engine system 11 including a turbocharger 10 according to one embodiment. The turbine 1 according to the present disclosure can be mounted on a turbocharger 10 for automobiles, ships, or industries (for example, for land-based power generation), for example. In the following embodiments, a turbine 1 mounted on a turbocharger 10 will be described as an example, but the turbine 1 according to the present disclosure is not limited to being mounted on a turbocharger 10. Furthermore, the working fluid of the turbine 1 does not need to be limited to exhaust gas. In other words, the turbine 1 according to the present disclosure may be configured as a standalone turbine 1 or may be configured in combination with a mechanism or device other than a compressor 13, as long as it is capable of converting working fluid energy into mechanical power (for example, rotational force). Furthermore, the use of the turbine 1 does not need to be limited.

[0013] 1, a turbocharger 10 according to some embodiments is configured to be driven by the energy of exhaust gas discharged from an engine (internal combustion engine) 12 and to compress a fluid (e.g., air). The turbocharger 10 includes a turbine 1 driven by the exhaust gas discharged from the engine 12, and a compressor 13 coaxially connected to the turbine 1 for supplying air compressed as the turbine 1 rotates to the engine 12.

[0014] The turbine 1 includes a turbine wheel 3 and a turbine housing 2 configured to rotatably accommodate the turbine wheel 3. The compressor 13 includes an impeller 131 and a compressor housing 132 configured to rotatably accommodate the impeller 131. The turbocharger 10 further includes a rotating shaft 14 to which the turbine wheel 3 is connected at one end and the impeller 131 is connected at the other end, and a bearing 15 configured to rotatably support the rotating shaft 14 between the turbine wheel 3 and the impeller 131. The turbocharger 10 may also include a bearing housing 16 arranged between the turbine housing 2 and the compressor housing 132 and configured to accommodate the bearing 15.

[0015] The turbine 1 is configured to rotate the turbine wheel 3 using the energy of exhaust gas discharged from the engine 12. The impeller 131 is coaxially connected to the turbine wheel 3 via the rotating shaft 14, and is therefore driven to rotate about the axis LA of the turbocharger 10 (rotating shaft 14) in conjunction with the rotation of the turbine wheel 3. The compressor 13 is configured to drive the impeller 131 to rotate about the axis LA, thereby drawing air (intake air, gas) into the compressor housing 132, compressing the air, and sending the compressed air to the engine 12. The compressed air sent from the compressor 13 to the engine 12 is used for combustion in the engine 12. Exhaust gas generated by combustion in the engine 12 is sent from the engine 12 to the turbine 1, causing the turbine wheel 3 to rotate.

[0016] In the illustrated embodiment, the impeller 131 is configured to guide air introduced along the axial direction of the impeller 131 (i.e., the extension direction of the axis line LA) to the outside in the radial direction of the impeller 131. The impeller 131 does not include an annular member that surrounds the outer periphery of the blades of the impeller 131. The turbine wheel 3 is configured to guide exhaust gas introduced from the outside in the radial direction of the turbine wheel 3 along the axial direction of the turbine wheel 3 (i.e., the extension direction of the axis line LA). The turbine wheel 3 does not include an annular member that surrounds the outer periphery of the blades of the turbine wheel 3.

[0017] (turbine housing) 2 is a schematic cross-sectional view along an axis LB of the scroll connection valve 5 of the turbine housing 2 according to one embodiment. As shown in FIG. 2, the turbine housing 2 according to some embodiments includes a turbine housing body 20 and a scroll connection valve 5 attached to the turbine housing body 20.

[0018] (Turbine housing body) As shown in Fig. 2, the turbine housing body 20 includes a scroll passage forming portion 21 that forms two scroll passages (a first scroll passage 41 and a second scroll passage 42), and a connecting passage forming portion 22 that forms a connecting passage 43 that includes a first branch passage 44, a second branch passage 45, and a merging passage 46. The turbine housing body 20 may further include an exhaust passage forming portion 23 that forms an exhaust passage 47 through which exhaust gas that has passed through the turbine wheel 3 flows. In this case, the first scroll passage 41, the second scroll passage 42, the connecting passage 43, and the exhaust passage 47 are formed inside the turbine housing body 20. The turbine housing body 20 is made of a metal material.

[0019] Each of the first scroll passage 41 and the second scroll passage 42 is a passage for introducing exhaust gas into the turbine wheel 3. Each of the first scroll passage 41 and the second scroll passage 42 is formed of a spiral passage extending in the circumferential direction around the axis LA on the outer periphery of the turbine wheel 3.

[0020] The first branch passage 44 is a passage branching off from one scroll passage (first scroll passage 41) of the two scroll passages 41, 42. The second branch passage 45 is a passage branching off from the other scroll passage (second scroll passage 42) of the two scroll passages 41, 42. The first branch passage 44 and the second branch passage 45 are joined together at a joining passage 46. The joining passage 46 is connected, via a communication port 48, to an exhaust passage 47 through which exhaust gas flows after passing through the turbine 1 (specifically, the turbine wheel 3).

[0021] In other words, one end of the first branch passage 44 is connected to the first scroll passage 41, and the other end is connected to the second branch passage 45 and the exhaust passage 47 at the junction passage 46. The second branch passage 45 is connected to the second scroll passage 42, and the other end is connected to the first branch passage 44 and the exhaust passage 47 at the junction passage 46. The first branch passage 44 and the second branch passage 45 communicate with each other so that exhaust gas can flow between the first scroll passage 41 and the second scroll passage 42, and also communicate with each other so that at least a portion of the exhaust gas flowing through the first scroll passage 41 and the second scroll passage 42 can be discharged to the exhaust passage 47, which has a lower pressure than the first scroll passage 41 and the second scroll passage 42.

[0022] (Scroll connection valve) When the scroll connection valve 5 is in a fully closed state (during a closing operation), the scroll connection valve 5 simultaneously seals the two branch flow paths (the first branch flow path 44 and the second branch flow path 45) in the junction flow path 46 and seals the junction flow path 46 and the exhaust flow path 47. When the scroll connection valve 5 is in a fully open state (during an opening operation), the scroll connection valve 5 releases the seal between the two branch flow paths (the first branch flow path 44 and the second branch flow path 45) in the junction flow path 46 and the seal between the junction flow path 46 and the exhaust flow path 47, thereby allowing exhaust gas to flow between these flow paths.

[0023] 2, the scroll connection valve 5 includes a valve element 6 and a valve rod 7 for driving the valve element 6. Hereinafter, the direction in which the axis LB of the valve element 6 extends will be referred to as the axial direction of the valve element 6, the direction perpendicular to the axis LB will be referred to as the radial direction of the valve element 6, and the circumferential direction around the axis LB will be referred to as the circumferential direction of the valve element 6. In the axial direction of the valve element 6, the side where the head 61 is provided will be defined as the tip side, and the side opposite to the tip side will be defined as the base side.

[0024] The scroll connection valve 5 is configured to be able to adjust the aperture of the valve element 6. Specifically, the scroll connection valve 5 further includes a rotation drive device including an actuator (not shown) for rotating the valve stem 7 about the valve axis RC. The scroll connection valve 5 is configured to be able to adjust the aperture of the valve element 6 to an aperture corresponding to the angular position of the valve stem 7 in the circumferential direction by rotating the valve stem 7 and the valve element 6 connected to the valve stem 7 about the valve axis RC. The scroll connection valve 5 is configured to be able to adjust the aperture of the valve element 6 to fully open, fully closed, or at least one intermediate aperture between fully open and fully closed.

[0025] The scroll connection valve 5 may include, instead of the above-described rotary drive device, an axial drive device including an actuator (not shown) for moving the valve rod 7 along the axial direction of the valve element 6. In this case, the scroll connection valve 5 may be configured to be able to adjust the opening degree of the valve element 6 to an opening degree corresponding to the axial position of the valve element 6 by moving the valve rod 7 and the valve element 6 connected to the valve rod 7 along the axial direction of the valve element 6.

[0026] 2, the valve body 6 (6A) according to the comparative example has a valve body shaft portion 60, a head portion 61, a flange portion 63, and an inclined portion 65 integrally formed therewith. The valve body 6 (6A) is made of a metal material.

[0027] The head 61 is provided on the axial tip side of the valve body 6, and is formed in a disk shape extending in a direction intersecting (orthogonal in the illustrated example) the axis LB of the valve body 6. The above-mentioned connection flow-path forming portion 22 has a branch wall 221 that separates the first branch flow path 44 and the second branch flow path 45. The head 61 extends in a direction intersecting (orthogonal in the illustrated example) the axis LB of the valve body 6, and has a head end surface 611 that faces the branch wall 221. The head end surface 611 is an end surface on the axial tip side of the head 61. The head end surface 611 abuts against the branch wall 221 in the junction flow path 46, so that the head 61 can separate the two branch flow paths 44, 45.

[0028] The flange 63 is formed in the shape of an annular plate extending radially outward (toward the outer periphery) of the valve body 6 relative to the head 61. The flange 63 is provided closer to the base end of the valve body 6 in the axial direction than the head 61. The exhaust flow path forming portion 23 described above has a seat wall surface 231. The seat wall surface 231 has a communication port 48 formed therein. The flange 63 extends in a direction intersecting (perpendicular to) the axis LB of the valve body 6 and has an annular seat surface 631 facing the seat wall surface 231. The annular seat surface 631 is an end face of the flange 63 on the tip side in the axial direction. The flange 63 can close the communication port 48 by abutting the annular seat surface 631 against the seat wall surface 231. Here, being able to close the communication port 48 means being able to disconnect the communication between the junction flow path 46 and the exhaust flow path 47 via the communication port 48.

[0029] However, the valve body 6 (6A) according to the comparative example has a shape that makes it difficult to simultaneously bring the head portion 61 into contact with the branch wall 221 and the flange portion 63 into contact with the seat wall surface 231. As shown in Fig. 2, when the flange portion 63 is brought into contact with the seat wall surface 231, a gap G is generated between the head portion end surface 611 of the head portion 61 and the branch wall 221. On the other hand, when the head portion 61 is brought into contact with the branch wall 221, a gap is generated between the seat surface 631 of the flange portion 63 and the seat wall surface 231.

[0030] (Deformation fee) As shown in FIGS. 3 to 7 , a turbine housing 2 according to some embodiments includes the turbine housing main body 20 described above, a scroll connection valve 5 including a valve element 6 (6B to 6E), and the valve stem 7 described above. As shown in FIGS. 3 , 4 , 6 , and 7 , the valve element 6 (6B, 6D, 6E) has the head portion 61 described above and a seat portion 62 extending radially outward (toward the outer periphery) of the valve element 6 relative to the head portion 61. The head portion 61 can separate the two branch flow paths 44, 45 by abutting against the branch wall 221 in the confluence flow path 46. The seat portion 62 can close the communication port 48 by abutting against the seat wall surface 231 described above.

[0031] 3, 6, and 7, the seat portion 62 has a deformation allowance DA for allowing the head portion 61 to abut against the branch wall 221 after the seat portion 62 abuts against the seat wall surface 231 during the closing operation of the scroll connection valve 5. In the scroll connection valve 5, a driving force that drives the valve element 6 applies a pressing force to the seat portion 62 abutting against the seat wall surface 231, pressing the seat portion 62 toward the tip side in the axial direction of the valve element 6. This pressing force causes at least a portion of the seat portion 62 to elastically deform within the range of the deformation allowance DA.

[0032] According to the above configuration, the seat portion 62 has a deformation allowance DA. In this case, during the closing operation of the scroll connection valve 5, after the seat portion 62 abuts against the seat wall surface 231, at least a portion of the seat portion 62 is deformed within the range of the deformation allowance DA, thereby allowing the head portion 61 to abut against the branch wall 221. This allows the turbine housing 2 to simultaneously seal the gap between the two branch flow passages 44, 45 in the junction flow passage 46 and the gap between the junction flow passage 46 and the exhaust flow passage 47. By simultaneously sealing the gap between the two branch flow passages 44, 45 and the gap between the junction flow passage 46 and the exhaust flow passage 47, it is possible to suppress exhaust gas leakage loss in the turbine 1, thereby improving the efficiency of the turbine 1.

[0033] Furthermore, according to the above configuration, the turbine housing 2 can have a simple structure by configuring the seat portion 62 to have a deformation allowance DA.

[0034] (First embodiment) Fig. 3 is a schematic cross-sectional view of the turbine housing 2 according to the first embodiment, taken along the axis LB of the scroll connection valve 5 when the scroll connection valve 5 is in a fully closed state (during a closing operation). Fig. 4 is a schematic cross-sectional view of the turbine housing 2 according to the first embodiment, taken along the axis LB of the scroll connection valve 5 when the scroll connection valve 5 is in a fully open state (during an opening operation).

[0035] 3 and 4, the seat portion 62 of the valve body 6B described above includes the flange portion 63 described above and an annular elastic seal member 64. In the embodiment shown in FIGS. 3 and 4, the valve body 6B is integrally formed with the valve body shaft portion 60, head portion 61, flange portion 63, and inclined portion 65. The valve body shaft portion 60, head portion 61, flange portion 63, elastic seal member 64, and inclined portion 65 are made of a metal material.

[0036] The valve body shaft 60 extends along the extension direction of the axis LB of the valve body 6, and an end (one end) on the tip side in the axial direction of the valve body 6 is connected to the head 61. An end (the other end) on the base side in the axial direction of the valve body 6 is connected to the valve rod 7.

[0037] The inclined portion 65 extends from the outer peripheral edge of the head 61 and is formed in a cylindrical shape that is inclined so that the distance from the axis LB of the valve body 6 increases with increasing distance from the head 61 in the direction of extension of the axis LB of the valve body 6. In the embodiment shown in Figures 3 and 4, one end of the inclined portion 65 is connected to the outer peripheral edge of the head 61, and the other end of the inclined portion 65 is connected to the inner peripheral end of the flange portion 63.

[0038] The elastic seal member 64 is disposed between the seat surface 631 of the flange 63 and the seat wall surface 231, and has the above-mentioned deformation allowance DA. That is, the elastic seal member 64 is configured to be able to contract along the axial direction of the valve body 6 due to the above-mentioned pressing force. The elastic seal member 64 is attached to the flange 63 by fitting such as riveting, welding, or adhesive. The elastic seal member 64 abuts against the seat wall surface 231 when the scroll connection valve 5 is in a fully closed state (during a closing operation), and is separated from the seat wall surface 231 when the scroll connection valve 5 is in a fully open state (during an opening operation).

[0039] According to the above configuration, the elastic seal member 64 has the above-mentioned deformation allowance DA. When the scroll connection valve 5 is closing, the elastic seal member 64 is elastically deformed, thereby simultaneously bringing the seat portion 62 into contact with the seat wall surface 231 and bringing the head portion 61 into contact with the branch wall 221. This allows the turbine housing 2 to simultaneously seal the gap between the two branch flow paths 44, 45 in the junction flow path 46 and the gap between the junction flow path 46 and the exhaust flow path 47.

[0040] In some embodiments, the elastic seal member 64 includes an annular first plate portion 641 extending radially of the valve body 6, an annular second plate portion 642 extending radially of the valve body 6, and an annular connecting portion 643 connecting the outer circumferential ends of the first plate portion 641 and the second plate portion 642. In the illustrated embodiment, the elastic seal member 64 has a C-shaped cross section. The first plate portion 641 abuts against an annular seat surface 631. The second plate portion 642 is provided so as to be movable toward and away from the seat wall surface 231, and abuts against the seat wall surface 231 when the valve body 6 is in the fully closed position.

[0041] According to the above configuration, the pressure of the exhaust gas in the confluence flow path 46 acts on the elastic sealing member 64 to apply a pressing force in a direction in which the inner peripheral end of the first plate portion 641 and the inner peripheral end of the second plate portion 642 widen (separate), and this pressing force effectively seals the gap between the seat surface 631 and the seat wall surface 231 with the elastic sealing member 64.

[0042] (Modification of the first embodiment) 5 is a schematic cross-sectional view of a turbine housing 2 according to a modification of the first embodiment, taken along the axis LB of the scroll connection valve 5 when the scroll connection valve 5 is in a fully open state (during an opening operation). In some of the embodiments described above, the elastic seal member 64 is attached to the seat surface 631 of the flange portion 63, but it may also be attached to the seat wall surface 231. In some embodiments, as shown in FIG. 5, the turbine housing 2 includes the turbine housing main body 20 described above, the scroll connection valve 5 including the valve disc 6C and the valve stem 7 described above, and an annular elastic seal member 64A. The valve disc 6C has the valve disc shaft portion 60, head portion 61, flange portion 63, and inclined portion 65 described above, similar to the valve disc 6A according to the comparative example.

[0043] The elastic seal member 64A is disposed between the seat surface 631 of the flange 63 and the seat wall surface 231, and has the above-mentioned deformation allowance DA. That is, the elastic seal member 64A is configured to be able to contract along the axial direction of the valve body 6 due to the above-mentioned pressing force. The elastic seal member 64A is made of a metal material. The elastic seal member 64A is attached to the seat wall surface 231 by fitting such as riveting, welding, or adhesive. The elastic seal member 64A can close the communication port 48 by abutting against the seat surface 631.

[0044] The elastic seal member 64A abuts against the seat surface 631 when the scroll connection valve 5 is in a fully closed state (during closing operation), and is separated from the seat surface 631 when the scroll connection valve 5 is in a fully open state (during opening operation).

[0045] According to the above configuration, the elastic seal member 64A has a deformation allowance DA. In this case, during the closing operation of the scroll connection valve 5, after the seat portion 62 abuts against the seat wall surface 231, at least a portion of the elastic seal member 64A is deformed within the range of the deformation allowance DA, thereby allowing the head portion 61 to abut against the branch wall 221. This allows the turbine housing 2 to simultaneously seal the gap between the two branch flow passages 44, 45 in the junction flow passage 46 and the gap between the junction flow passage 46 and the exhaust flow passage 47. By simultaneously sealing the gap between the two branch flow passages 44, 45 and the gap between the junction flow passage 46 and the exhaust flow passage 47, it is possible to suppress exhaust gas leakage loss in the turbine 1, thereby improving the efficiency of the turbine 1.

[0046] Furthermore, according to the above-described configuration, the turbine housing 2 can have a simple structure by configuring the elastic seal member 64A to have a deformation allowance DA.

[0047] In some embodiments, the elastic seal member 64A includes, as shown in FIG. 5 , an annular first plate portion 641A extending radially of the valve body 6, an annular second plate portion 642A extending radially of the valve body 6, and an annular connecting portion 643A connecting the outer circumferential ends of the first plate portion 641A and the second plate portion 642A. In the illustrated embodiment, the elastic seal member 64A has a C-shaped cross section. The first plate portion 641A is removably mounted on an annular seat surface 631 and is configured to abut against the annular seat surface 631 when the valve body 6 is in the fully closed position. The second plate portion 642A abuts against the seat wall surface 231.

[0048] According to the above configuration, the pressure of the exhaust gas in the confluence flow path 46 acts on the elastic sealing member 64A with a pressing force in a direction in which the inner peripheral end of the first plate portion 641A and the inner peripheral end of the second plate portion 642A widen (separate) from each other, and this pressing force effectively seals the gap between the seat surface 631 and the seat wall surface 231 with the elastic sealing member 64A.

[0049] It is easier to attach the elastic seal member 64 to the seat surface 631 of the flange 63 than to attach the elastic seal member 64A to the seat wall surface 231. Furthermore, attaching the elastic seal member 64 to the seat surface 631 of the flange 63 reduces the area of ​​contact with the turbine housing main body 20 compared to attaching the elastic seal member 64A to the seat wall surface 231, and reduces the amount of heat input from the turbine housing main body 20, thereby suppressing thermal damage to the elastic seal member.

[0050] (Second embodiment) 6 is a schematic cross-sectional view of a turbine housing 2 according to a second embodiment, taken along an axis LB of the scroll connection valve 5 when the scroll connection valve 5 is in a fully closed state. In some embodiments, the valve body 6 (6D) includes the head portion 61 described above, the inclined portion 65 described above, and a seat portion 62, as shown in FIG. 6. The seat portion 62 includes a flange portion 66 that extends radially outward of the valve body 6 beyond the head portion 61 and has an annular seat surface 661 facing the seat wall surface 231.

[0051] The flange 66 has an inner peripheral end connected to the inclined portion 65 and has the deformation allowance DA. That is, the outer peripheral end of the flange 66 can be bent by elastic deformation toward the base end in the axial direction of the valve body 6 from the inner peripheral end due to the pressing force. The flange 66 may have a base point of elastic deformation at a connection point P1 between the flange 66 and the inclined portion 65, or at a connection point P2 between the inclined portion 65 and the head portion 61. Furthermore, to facilitate elastic deformation of the flange 66, the thickness T1 of the flange 66 may be thinner than the thickness T2 of the head portion. Furthermore, the thickness T1 of the flange 66 may be thinner than the thickness of the inclined portion 65.

[0052] According to the above configuration, the flange portion 66 has the deformation allowance DA. During the closing operation of the scroll connection valve 5, elastic deformation of the flange portion 66 can simultaneously bring the seat portion 62 into contact with the seat wall surface 231 and bring the head portion 61 into contact with the branch wall 221. This allows the turbine housing 2 to simultaneously seal the gap between the two branch passages 44, 45 in the junction passage 46 and the gap between the junction passage 46 and the exhaust passage 47.

[0053] 6, the flange 66 has an annular protrusion 662 that protrudes toward the seat wall surface 231. The annular protrusion 662 protrudes from the annular seat surface 631 toward the tip side of the valve body 6 in the axial direction.

[0054] According to the above configuration, by disposing the annular protrusion 662 of the flange 66 on the radially outer side of the valve body 6, it is possible to increase the bending moment acting on the portion where the annular protrusion 662 and the seat wall surface 231 abut. Increasing the bending moment improves the sealing performance between the annular protrusion 662 and the seat wall surface 231. Note that, in order to increase the bending moment, it is preferable to provide the annular protrusion 662 at a position away from the axis LB. In the embodiment shown in FIG. 6, the annular protrusion 662 is formed on the outer peripheral edge of the seat surface 631 of the flange 66.

[0055] (Third embodiment) 7 is a schematic cross-sectional view of a turbine housing 2 according to a third embodiment, taken along the axis LB of the scroll connection valve 5 when the scroll connection valve 5 is in a fully closed state. In some embodiments, the valve body 6 (6E) includes the above-described valve body shaft portion 60, the above-described head portion 61, the above-described inclined portion 65, and a seat portion 62, as shown in FIG. 7. The seat portion 62 extends radially outward of the valve body 6 beyond the head portion 61 and includes an annular plate member 67 having an annular seat surface 671 facing the seat wall surface 231.

[0056] The annular plate member 67 is configured separately from the valve disc shaft portion 60, the head portion 61, and the inclined portion 65. The inner peripheral end of the annular plate member 67 is attached to the valve disc shaft portion 60. In the illustrated embodiment, the valve disc shaft portion 60 is formed with a stepped surface 601 that makes the base end side smaller in diameter than the tip end side, and a threaded portion 602 that is formed on at least a portion of the outer circumferential surface on the base end side of the stepped surface 601. The annular plate member 67 is fixed to the valve disc shaft portion 60 by sandwiching an inner peripheral end 673 of the annular plate member 67 between the stepped surface 601 and a nut member 68 having a threaded portion 681 that screws onto the threaded portion 602.

[0057] The annular plate member 67 includes the annular inner peripheral end 673, an annular outer peripheral end 675 having a seat surface 671, and an annular connecting plate portion 674 connecting the outer peripheral end 675 and the inner peripheral end 673. The connecting plate portion 674 is bent relative to the inner peripheral end 673 toward the base end, and is bent relative to the outer peripheral end 675 toward the tip end.

[0058] The annular plate member 67 has a deformation allowance DA. That is, the annular plate member 67 can be bent by elastic deformation toward the base end at least at the outer peripheral end 675 due to the pressing force. The annular plate member 67 may have a connection part P3 between the outer peripheral end 675 and the connecting plate part 674 as a base point for elastic deformation.

[0059] According to the above configuration, the annular plate member 67 has the above-mentioned deformation allowance DA. When the scroll connection valve 5 is closing, the annular plate member 67 is elastically deformed, thereby simultaneously bringing the seat portion 62 into contact with the seat wall surface 231 and bringing the head portion 61 into contact with the branch wall 221. This allows the turbine housing 2 to simultaneously seal the gap between the two branch flow passages 44, 45 in the junction flow passage 46 and the gap between the junction flow passage 46 and the exhaust flow passage 47.

[0060] Furthermore, according to the above configuration, by making the annular plate member 67 a separate member from the head 61, the inclined portion 65, and the valve disc shaft portion 60, it is easier to form a deformation allowance DA in the annular plate member 67 than when the annular plate member 67 is integral with the head 61, the inclined portion 65, and the valve disc shaft portion 60, and it is possible to position the deformation starting point P3 of the annular plate member 67 radially inward of the valve disc 6. By positioning the deformation starting point P3 of the annular plate member 67 radially inward of the valve disc 6, it is possible to increase the bending moment acting on the portion where the seat portion 62 and the seat wall surface 231 abut. By increasing the bending moment, it is possible to improve the sealing performance between the seat portion 62 and the seat wall surface 231.

[0061] 7, the annular plate member 67 has an annular curved portion 672 that curves so as to protrude toward the seat wall surface 231. In the illustrated embodiment, the annular curved portion 672 is formed on the outer periphery of the outer periphery end 675. The curved portion 672 has a convex shape that protrudes toward the tip side in the axial direction of the valve body 6.

[0062] According to the above configuration, by disposing the annular curved portion 672 of the annular plate member 67 on the outer side in the radial direction of the valve body 6, it is possible to increase the bending moment acting on the portion where the annular curved portion 672 abuts against the seat wall surface 231. By increasing the bending moment, it is possible to improve the sealing performance between the annular curved portion 672 and the seat wall surface 231.

[0063] As shown in Fig. 2, a turbine 1 according to some embodiments includes the above-described turbine housing 2 and the above-described turbine wheel 3. As shown in Fig. 1, a turbocharger 10 according to some embodiments includes the above-described turbine 1 and the above-described compressor 13. In these cases, the turbine housing 2 can simultaneously seal the space between the two branch passages 44, 45 in the joining passage 46 and the space between the joining passage 46 and the exhaust passage 47. This can suppress leakage loss of exhaust gas in the turbine 1, thereby improving the efficiency of the turbine 1 and the turbocharger 10.

[0064] In this specification, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement strictly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions representing shapes such as a rectangular shape or a cylindrical shape not only represent rectangular shapes or cylindrical shapes in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. Furthermore, in this specification, the expressions "comprise," "include," or "have" a component are not exclusive expressions that exclude the presence of other components.

[0065] The present disclosure is not limited to the above-described embodiments, but also includes modifications of the above-described embodiments and appropriate combinations of these embodiments. The turbine housing 2 of the present disclosure can be applied to double scroll turbines and twin scroll turbines.

[0066] The contents of the above-described embodiments can be understood, for example, as follows.

[0067] 1) A turbine housing (2) according to at least one embodiment of the present disclosure comprises: A turbine housing (2) in which two scroll passages (41, 42) are formed, a scroll passage forming portion (21) that forms the two scroll passages (41, 42); a connecting-flow-path forming section (22) that forms a connecting flow path (43) including a first branch flow path (44) branching from one scroll flow path (41) of the two scroll flow paths (41, 42), a second branch flow path (45) branching from the other scroll flow path (42) of the two scroll flow paths (41, 42), and a confluence flow path (46) where the first branch flow path (44) and the second branch flow path (45) join and that communicates, via a communication port (48), with an exhaust flow path (47) through which exhaust gas that has passed through a turbine wheel (3) flows, the connecting-flow-path forming section (22) having a branch wall (221) that separates the first branch flow path (44) and the second branch flow path (45); a turbine housing body (20) including: a head portion (61) that can separate the two branch flow paths (44, 45) by contacting the branch wall (221) in the junction flow path (46); a seat portion (62) extending outward from the head portion (61) toward the outer periphery thereof, the seat portion (62) being capable of closing the communication port (48) by abutting against a seat wall surface (231) of the turbine housing (2). and a scroll connection valve (5) including: The seat portion (62) has a deformation allowance (DA) for allowing the head portion (61) to abut against the branch wall (221) after the seat portion (62) abuts against the seat wall surface (231) during the closing operation of the scroll connection valve (5).

[0068] According to the above configuration 1), the seat portion (62) has a deformation allowance (DA). In this case, during the closing operation of the scroll connection valve (5), after the seat portion (62) contacts the seat wall surface (231), at least a portion of the seat portion (62) is deformed within the deformation allowance (DA), thereby allowing the head portion (61) to contact the branch wall (221). This allows the turbine housing (2) to simultaneously seal the gap between the two branch flow paths (44, 45) in the junction flow path (46) and the gap between the junction flow path (46) and the exhaust flow path (47). By simultaneously sealing the gap between the two branch flow paths (44, 45) and the gap between the junction flow path (46) and the exhaust flow path (47), it is possible to reduce leakage loss of exhaust gas in the turbine (1), thereby improving the efficiency of the turbine (1).

[0069] Furthermore, according to the above configuration 1), the turbine housing (2) can be simplified in structure by providing the seat portion (62) with a deformation allowance (DA).

[0070] 2) In some embodiments, the turbine housing (2) according to 1) above, The seat portion (62) is a flange portion (63) extending radially outward of the valve body (6) beyond the head portion (61) and having an annular seat surface (631) facing the seat wall surface (231) with a gap therebetween; and an annular elastic sealing member (64) having the deformation allowance (DA) attached to the flange portion (63), the elastic sealing member (64) being arranged between the seat surface (631) of the flange portion (63) and the seat wall surface (231).

[0071] According to the configuration 2), the elastic seal member (64) has the deformation allowance (DA). When the scroll connection valve (5) is closing, the elastic seal member (64) is elastically deformed, thereby simultaneously bringing the seat portion (62) into contact with the seat wall surface (231) and bringing the head portion (61) into contact with the branch wall (221). This allows the turbine housing (2) to simultaneously seal the gap between the two branch flow paths (44, 45) in the junction flow path (46) and the gap between the junction flow path (46) and the exhaust flow path (47).

[0072] 3) In some embodiments, the turbine housing (2) according to 2) above, The elastic seal member (64) a first plate portion (641) extending along the radial direction of the valve body (6) and abutting against the annular seat surface (631); a second plate portion (642) extending along the radial direction of the valve body (6), the second plate portion (642) being provided so as to be able to approach and separate from the seat wall surface (231), and abutting against the seat wall surface (231) when the valve body (6) is in the fully closed position; and a connecting portion (643) connecting the outer peripheral end of the first plate portion (641) and the outer peripheral end of the second plate portion (642).

[0073] According to the configuration 3) above, the pressure of the exhaust gas in the merging flow path (46) acts on the elastic sealing member (64) with a pressing force in a direction in which the inner peripheral end of the first plate portion (641) and the inner peripheral end of the second plate portion (642) widen (separate from each other), and this pressing force effectively causes the elastic sealing member (64) to seal between the seat surface (631) and the seat wall surface (231).

[0074] 4) In some embodiments, the turbine housing (2) according to 1) above, The valve body (6) The valve body (6) further includes an inclined portion (65) extending from the outer peripheral edge of the head portion (61) and inclined so that the distance from the axis increases with increasing distance from the head portion (61) in the direction of extension of the axis of the valve body (6), the seat portion (62) includes a flange portion (66) that extends radially outward of the valve body (6) beyond the head portion (61) and has an annular seat surface (661) that faces the seat wall surface (231) via a gap, and whose inner peripheral end is connected to the inclined portion (65), The flange portion (66) has the deformation allowance (DA).

[0075] According to the configuration of 4), the flange portion (66) has the deformation allowance (DA). During the closing operation of the scroll connection valve (5), the flange portion (66) is elastically deformed, thereby simultaneously bringing the seat portion (62) into contact with the seat wall surface (231) and bringing the head portion (61) into contact with the branch wall (221). This allows the turbine housing (2) to simultaneously seal the gap between the two branch flow paths (44, 45) in the junction flow path (46) and the gap between the junction flow path (46) and the exhaust flow path (47).

[0076] 5) In some embodiments, the turbine housing (2) according to 4) above, The flange (66) has an annular projection (662) that projects toward the seat wall surface (231).

[0077] According to the configuration 5), the annular protrusion (662) of the flange (66) is disposed radially outward from the valve body (6), thereby increasing the bending moment acting on the contact portion between the annular protrusion (662) and the seat wall surface (231). Increasing the bending moment improves the sealing performance between the annular protrusion (662) and the seat wall surface (231).

[0078] 6) In some embodiments, the turbine housing (2) according to 1) above, The valve body (6) further includes a valve body shaft portion (60) extending along the extension direction of the axis of the valve body (6) and having one end connected to the head portion (61), the seat portion (62) is an annular plate member (67) that extends radially outward of the valve body (6) beyond the head portion (62) and has an annular seat surface (671) that faces the seat wall surface (231) via a gap, and the annular plate member (67) has an inner peripheral end attached to the valve body shaft portion (60), The annular plate member (67) has the deformation allowance (DA).

[0079] According to the configuration of 6), the annular plate member (67) has the deformation allowance (DA). When the scroll connection valve (5) is closing, the annular plate member (67) is elastically deformed, thereby simultaneously bringing the seat portion (62) into contact with the seat wall surface (231) and bringing the head portion (61) into contact with the branch wall (221). This allows the turbine housing (2) to simultaneously seal the gap between the two branch flow paths (44, 45) in the junction flow path (46) and the gap between the junction flow path (46) and the exhaust flow path (47).

[0080] According to the configuration of 6), the annular plate member (67) is formed as a separate member from the head portion (62), the inclined portion (65), and the valve disc shaft portion (60). This makes it easier to provide a deformation allowance (DA) in the annular plate member (67) and to position the deformation starting point of the annular plate member (67) radially inward of the valve disc (6), compared to when the annular plate member (67) is integral with the head portion (62), the inclined portion (65), and the valve disc shaft portion (60). Positioning the deformation starting point of the annular plate member (67) radially inward of the valve disc (6) increases the bending moment acting on the contact portion between the seat portion (62) and the seat wall surface (231). Increasing the bending moment improves the sealing performance between the seat portion (62) and the seat wall surface (231).

[0081] 7) In some embodiments, the turbine housing (2) according to 6) above, The annular plate member (67) has an annular curved portion (672) that curves and protrudes toward the seat wall surface (231).

[0082] According to the configuration 7), the annular curved portion (672) of the annular plate member (67) is disposed radially outward from the valve body (6), thereby increasing the bending moment acting on the contact portion between the annular curved portion (672) and the seat wall surface (231). Increasing the bending moment improves the sealing performance between the annular curved portion (672) and the seat wall surface (231).

[0083] 8) The turbine housing (2) according to at least one embodiment of the present disclosure comprises: A turbine housing (2) in which two scroll passages (41, 42) are formed, a scroll passage forming portion (21) that forms the two scroll passages (41, 42); a connecting-flow-path forming section (22) that forms a connecting flow path (43) including a first branch flow path (44) branching from one scroll flow path (41) of the two scroll flow paths (41, 42), a second branch flow path (45) branching from the other scroll flow path (42) of the two scroll flow paths (41, 42), and a confluence flow path (46) where the first branch flow path (44) and the second branch flow path (45) join and that communicates, via a communication port (48), with an exhaust flow path (47) through which exhaust gas that has passed through a turbine wheel (3) flows, the connecting-flow-path forming section (22) having a branch wall (221) that separates the first branch flow path (44) and the second branch flow path (45); a turbine housing body (20) including: a head portion (61) that can separate the two branch flow paths (44, 45) by contacting the branch wall (221) in the junction flow path (46); a flange portion (63) extending radially outward from the head portion (61) and having an annular seat surface (631) facing a seat wall surface (231) of the turbine housing (2) via a gap; a scroll connection valve (5) including an annular elastic seal member (64A) disposed between the seat surface (631) and the seat wall surface (231) and attached to the seat wall surface (231), the elastic seal member (64A) being capable of closing the communication opening (48) by coming into contact with the seat surface (631); The elastic sealing member (64A) has a deformation allowance (DA) that allows the head portion (61) to abut against the branch wall (221) after the elastic sealing member (64A) abuts against the seat surface (631) during the closing operation of the scroll connection valve (5).

[0084] According to the configuration of 8), the elastic seal member (64A) has a deformation allowance (DA). In this case, during the closing operation of the scroll connection valve (5), after the seat portion (62) abuts against the seat wall surface (231), at least a portion of the elastic seal member (64A) is deformed within the deformation allowance (DA), thereby allowing the head portion (61) to abut against the branch wall (221). This allows the turbine housing (2) to simultaneously seal the gap between the two branch flow paths (44, 45) in the junction flow path (46) and the gap between the junction flow path (46) and the exhaust flow path (47). By simultaneously sealing the gap between the two branch flow paths (44, 45) and the gap between the junction flow path (46) and the exhaust flow path (47), it is possible to reduce exhaust gas leakage loss in the turbine (1), thereby improving the efficiency of the turbine (1).

[0085] According to the above configuration 8), the turbine housing (2) can be simplified in structure by providing the elastic seal member (64A) with a deformation allowance (DA).

[0086] 9) The turbine (1) according to at least one embodiment of the present disclosure comprises: A turbine housing (2) according to any one of 1) to 8), and a turbine wheel (3) rotatably accommodated in the turbine housing.

[0087] According to the configuration 9), the turbine housing (2) can simultaneously seal the gap between the two branch flow paths (44, 45) in the junction flow path (46) and the gap between the junction flow path (46) and the exhaust flow path (47). This can reduce leakage loss of exhaust gas in the turbine (1), thereby improving the efficiency of the turbine (1).

[0088] 10) The turbocharger (10) according to at least one embodiment of the present disclosure includes: a turbine (1) driven by exhaust gas discharged from an engine (12), the turbine (1) being as described in 9) above; The compressor (13) is coaxially connected to the turbine (1) and supplies compressed air to the engine (12) as the turbine rotates.

[0089] According to the configuration 10), the turbine housing (2) can simultaneously seal the gap between the two branch passages (44, 45) in the junction passage (46) and the gap between the junction passage (46) and the exhaust passage (47). This can reduce leakage loss of exhaust gas in the turbine (1), thereby improving the efficiency of the turbocharger (10). [Explanation of symbols]

[0090] 1 turbine 2 Turbine housing 3 Turbine Wheel 5 Scroll Connection Valve 6 Valve body 10. Turbocharger 11 Engine System 12 Engine 13 Compressor 14 Rotating shaft 15 Bearings 16 Bearing housing 20 Turbine housing body 21 Scroll flow passage forming section 22 Connection flow path forming portion 23 Exhaust flow path forming section 41 First scroll passage 42 Second scroll passage 43 Connecting Channel 44 First branch channel 45 Second branch channel 46 Confluence 47 Exhaust flow path 48 Connecting port 60 Valve body shaft 61 Head 62 Seat section 63,66 Tsuba section 64, 64A Elastic sealing member 65 Slope 67 Annular plate member 68 Nut material 131 Impeller 132 Compressor housing

Claims

1. A turbine housing in which two scroll passages are formed, a scroll flow passage forming portion that forms the two scroll flow passages; a connecting passage forming section that forms connecting passages including a first branch passage branching from one of the two scroll passages, a second branch passage branching from the other of the two scroll passages, and a confluence passage where the first branch passage and the second branch passage merge and that communicates via a communication port with an exhaust passage through which exhaust gas that has passed through a turbine wheel flows, the connecting passage forming section having a branch wall that separates the first branch passage and the second branch passage; a turbine housing body including: a head portion that can separate the two branch flow paths by contacting the branch wall in the joining flow path; a seat portion extending radially outward from the head portion and capable of closing the communication port by contacting a seat wall surface of the turbine housing. a scroll connection valve including: the seat portion has a deformation allowance for allowing the head portion to abut against the branch wall after the seat portion abuts against the seat wall surface during a closing operation of the scroll connection valve, The seat portion is a flange portion extending radially outward of the head portion of the valve body and having an annular seat surface facing the seat wall surface with a gap therebetween; an annular elastic seal member having the deformation allowance attached to the flange portion, the elastic seal member being disposed between the seat surface of the flange portion and the seat wall surface; The elastic sealing member is a first plate portion extending along a radial direction of the valve body and abutting against the annular seat surface; a second plate portion extending along a radial direction of the valve body, the second plate portion being provided so as to be able to come into contact with and separate from the seat wall surface, and the second plate portion being in contact with the seat wall surface when the valve body is in a fully closed position; a connecting portion connecting an outer peripheral end of the first plate portion and an outer peripheral end of the second plate portion, Turbine housing.

2. A turbine housing in which two scroll flow paths are formed, a scroll flow passage forming portion that forms the two scroll flow passages; a connecting passage forming section that forms connecting passages including a first branch passage branching from one of the two scroll passages, a second branch passage branching from the other of the two scroll passages, and a confluence passage where the first branch passage and the second branch passage merge and that communicates via a communication port with an exhaust passage through which exhaust gas that has passed through a turbine wheel flows, the connecting passage forming section having a branch wall that separates the first branch passage and the second branch passage; a turbine housing body including: a head portion that can separate the two branch flow paths by contacting the branch wall in the joining flow path; a seat portion extending radially outward from the head portion and capable of closing the communication port by contacting a seat wall surface of the turbine housing. a scroll connection valve including: the seat portion has a deformation allowance for allowing the head portion to abut against the branch wall after the seat portion abuts against the seat wall surface during a closing operation of the scroll connection valve, The valve body is The valve body further includes an inclined portion extending from an outer peripheral edge of the head portion and inclined so that the distance from the axis increases with increasing distance from the head portion in the extension direction of the axis of the valve body, the seat portion includes a flange portion having an annular seat surface that extends radially outward of the head portion of the valve body and faces the seat wall surface with a gap therebetween, the flange portion having an inner peripheral end connected to the inclined portion, The flange portion has the deformation allowance. Turbine housing.

3. The flange portion has an annular protrusion that protrudes toward the seat wall surface. The turbine housing of claim 2 .

4. A turbine housing in which two scroll flow paths are formed, a scroll flow passage forming portion that forms the two scroll flow passages; a connecting passage forming section that forms connecting passages including a first branch passage branching from one of the two scroll passages, a second branch passage branching from the other of the two scroll passages, and a confluence passage where the first branch passage and the second branch passage merge and that communicates via a communication port with an exhaust passage through which exhaust gas that has passed through a turbine wheel flows, the connecting passage forming section having a branch wall that separates the first branch passage and the second branch passage; a turbine housing body including: a head portion that can separate the two branch flow paths by contacting the branch wall in the joining flow path; a seat portion extending radially outward from the head portion and capable of closing the communication port by contacting a seat wall surface of the turbine housing. a scroll connection valve including: the seat portion has a deformation allowance for allowing the head portion to abut against the branch wall after the seat portion abuts against the seat wall surface during a closing operation of the scroll connection valve, The valve body further includes a valve body stem portion extending along an extension direction of the axis of the valve body and having one end connected to the head portion, the seat portion is an annular plate member having an annular seat surface that extends radially outward of the head portion of the valve body and faces the seat wall surface with a gap therebetween, the annular plate member having an inner peripheral end attached to the valve body shaft portion, The annular plate member has the deformation allowance. Turbine housing.

5. The annular plate member has an annular curved portion that is curved so as to protrude toward the seat wall surface. The turbine housing of claim 4 .

6. A turbine housing in which two scroll passages are formed, a scroll flow passage forming portion that forms the two scroll flow passages; a connecting passage forming section that forms connecting passages including a first branch passage branching from one of the two scroll passages, a second branch passage branching from the other of the two scroll passages, and a confluence passage where the first branch passage and the second branch passage merge and that communicates via a communication port with an exhaust passage through which exhaust gas that has passed through a turbine wheel flows, the connecting passage forming section having a branch wall that separates the first branch passage and the second branch passage; a turbine housing body including: a head portion that can separate the two branch flow paths by contacting the branch wall in the joining flow path; a flange portion extending radially outward beyond the head portion and having an annular seat surface facing a seat wall surface of the turbine housing with a gap therebetween. a scroll connection valve including: an annular elastic seal member disposed between the seat surface and the seat wall surface and attached to the seat wall surface, the elastic seal member being capable of closing the communication opening by abutting against the seat surface; the elastic seal member has a deformation allowance for allowing the head portion to abut against the branch wall after the elastic seal member abuts against the seat surface during a closing operation of the scroll connection valve, The elastic sealing member is a first plate portion extending along a radial direction of the valve body, being provided so as to be able to come into contact with and separate from the annular seat surface, and being in contact with the annular seat surface when the valve body is in a fully closed position; a second plate portion extending along a radial direction of the valve body and abutting against the seat wall surface; a connecting portion connecting an outer peripheral end of the first plate portion and an outer peripheral end of the second plate portion, Turbine housing.

7. A turbine housing according to any one of claims 1 to 6; a turbine wheel rotatably accommodated in the turbine housing, Turbine.

8. A turbine driven by exhaust gas discharged from an engine, the turbine according to claim 7; a compressor coaxially connected to the turbine for supplying compressed air to the engine as the turbine rotates; Supercharger.

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