JP7300908B2 - Turbine housing and turbocharger - Google Patents

Description

The present disclosure relates to a turbine housing and a turbocharger comprising the turbine housing.

Conventionally, some turbine housings are configured to accommodate wastegate valves (see, for example, Patent Document 1). Patent Document 1 describes a wheel accommodation space in which a turbine wheel is accommodated, a discharge passage for discharging exhaust gas that has passed through the turbine wheel to the outside of the turbine housing, and exhaust gas that bypasses the wheel accommodation space and flows into the discharge passage. A turbine housing is disclosed in which a bypass flow path is formed. A waste gate valve is arranged to close the outlet of the bypass channel. The boost pressure of the turbocharger is adjusted by controlling the opening amount of the waste gate valve and adjusting the flow rate of the exhaust gas passing through the bypass passage.

In order to accommodate the waste gate valve, the discharge passage described in Patent Literature 1 has a shape that expands radially outward from the wheel accommodation space. The tubular portion of the turbine housing has an elliptical cross-sectional shape, and the inner wall surface of the tubular portion extending in the axial direction of the turbine housing defines the discharge passage.

JP 2018-091275 A

The inventors of the present invention have found that the turbine housing as described in Patent Document 1 cannot reduce the flow velocity of the exhaust gas flowing through the exhaust passage, resulting in pressure loss, and there is a risk that a sufficient static pressure recovery effect cannot be obtained. I found out. If the static pressure recovery effect of the exhaust gas is small, there is a risk of hindering the performance improvement of the turbocharger.

In view of the circumstances described above, an object of at least one embodiment of the present disclosure is to provide a turbine housing and a turbocharger that can improve the performance of the turbocharger by improving the static pressure recovery effect in the exhaust flow path. to do.

A turbine housing according to the present disclosure includes:
A turbine housing configured to house a turbine wheel and a wastegate valve, comprising:
a scroll passage forming portion for forming a scroll passage for introducing exhaust gas from the outside of the turbine housing into the wheel accommodation space in which the turbine wheel is accommodated;
a discharge passage forming portion that forms a discharge passage for discharging the exhaust gas that has passed through the turbine wheel to the outside of the turbine housing;
a bypass flow path forming part that forms a bypass flow path that bypasses the wheel housing space from the scroll flow path and sends the exhaust gas to the discharge flow path,
A valve housing space for housing the waste gate valve is formed inside the discharge passage forming portion,
the flow path wall surface of the discharge flow path forming portion includes, at least in part in the circumferential direction, an inclined surface that is inclined so that the distance from the axis of the turbine housing increases toward the outlet side of the discharge flow path;
The inclined surface exists in a range that overlaps the valve housing space in the circumferential direction in a plan view of the turbine housing along the axis.

The turbocharger according to the present disclosure is
a turbine wheel;
the turbine housing;
and a waste gate valve configured to open and close the bypass channel.

According to at least one embodiment of the present disclosure, a turbine housing and a turbocharger are provided that can improve the performance of the turbocharger by improving the static pressure recovery effect in the exhaust flow path.

1 is a schematic configuration diagram schematically showing the configuration of a turbocharger according to an embodiment of the present disclosure; FIG. 1 is a schematic cross-sectional view of a turbocharger with a turbine housing according to one embodiment of the present disclosure; FIG. 1 is a schematic perspective view of a turbine housing in accordance with one embodiment of the present disclosure; FIG. 4 is a schematic cross-sectional view taken along line BB of FIG. 3 of a turbine housing according to an embodiment of the present disclosure; FIG. 1 is a schematic cross-sectional view of a turbine housing according to an embodiment of the present disclosure, showing a state in which a wastegate valve is arranged; FIG. FIG. 4 is a schematic cross-sectional view showing a cross-section perpendicular to the axis of the turbine housing according to one embodiment of the present disclosure, as seen from the exit side of the discharge channel; 1 is a schematic cross-sectional view of a turbocharger provided with a turbine housing according to a comparative example; FIG. FIG. 4 is a schematic cross-sectional view of a turbine housing according to a comparative example, taken along the line BB in FIG. 3; FIG. 4 is a diagram for explaining pressure distribution of exhaust gas in a turbine housing according to an embodiment of the present disclosure; FIG. FIG. 5 is a diagram for explaining the pressure distribution of exhaust gas in a turbine housing according to a comparative example; FIG. 4 is a diagram for explaining pressure distribution of exhaust gas in a turbine housing according to an embodiment of the present disclosure; FIG. FIG. 5 is a diagram for explaining the pressure distribution of exhaust gas in a turbine housing according to a comparative example;

Several embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as the embodiment or shown in the drawings are not meant to limit the scope of the present disclosure, but are merely illustrative examples. do not have.
For example, expressions denoting relative or absolute arrangements such as "in a direction", "along a direction", "parallel", "perpendicular", "center", "concentric" or "coaxial" are strictly not only represents such an arrangement, but also represents a state of relative displacement with a tolerance or an angle or distance to the extent that the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous", which express that things are in the same state, not only express the state of being strictly equal, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
For example, expressions that express shapes such as squares and cylinders do not only represent shapes such as squares and cylinders in a geometrically strict sense, but also include irregularities and chamfers to the extent that the same effect can be obtained. The shape including the part etc. shall also be represented.
On the other hand, the expressions "comprising", "including", or "having" one component are not exclusive expressions excluding the presence of other components.
In addition, the same code|symbol may be attached|subjected about the same structure and description may be abbreviate|omitted.

(Turbocharger configuration)
FIG. 1 is a schematic configuration diagram that schematically shows the configuration of a turbocharger according to an embodiment of the present disclosure. As shown in FIG. 1, a turbocharger 1 according to some embodiments includes a turbine wheel 11, a compressor wheel 12, and a rotating shaft 13 mechanically coupled to each of the turbine wheel 11 and compressor wheel 12. , a housing 14 configured to house the turbine wheel 11 , the compressor wheel 12 and the rotating shaft 13 .

As shown in FIG. 1 , the rotating shaft 13 has a longitudinal direction, one longitudinal end is mechanically connected to the turbine wheel 11 , and the other longitudinal end is connected to the compressor wheel 12 . mechanically connected. The rotating shaft 13 is rotatably supported by bearings 15 . Therefore, the turbine wheel 11 and the compressor wheel 12 are integrally rotatable via the rotating shaft 13 .

The housing 14 comprises a turbine housing 3 that accommodates the turbine wheel 11 therein, as shown in FIG. In the illustrated embodiment, the housing 14 includes the turbine housing 3 described above, a compressor housing 16 containing the compressor wheel 12 and a bearing housing 17 containing the bearings 15 . The bearing housing 17 is arranged between the turbine housing 3 and the compressor housing 16, and is mechanically connected to each of the turbine housing 3 and the compressor housing 16 by fastening members such as bolts and V-clamps.

As shown in FIG. 1, the turbine wheel 11 is provided in an exhaust passage 18 for sending exhaust gas discharged from an engine body 10 (internal combustion engine) that generates exhaust gas downstream in the flow direction of the exhaust gas. The compressor wheel 12 is provided in an intake passage 19 through which combustion gas sent to the engine body 10 flows. Combustion gas includes, for example, fresh air, EGR gas, and a mixture thereof.

In the turbocharger 1, a turbine wheel 11 is rotationally driven by exhaust gas discharged from an engine body 10 and flowing through an exhaust passage 18, and a compressor wheel 12 rotationally driven in conjunction with the turbine wheel 11 drives combustion gas flowing through an intake passage 19. is configured to compress the

As shown in FIG. 1, the turbocharger 1 opens and closes a bypass passage 20 for sending the exhaust gas discharged from the engine body 10 from the upstream side to the downstream side of the turbine wheel 11 without passing through the turbine wheel 11. It further comprises a wastegate valve 21 which is configurable.

As shown in FIG. 1 , the upstream side of the exhaust gas flow direction of the turbine wheel 11 in the exhaust gas passage 18 is defined as an upstream exhaust gas passage 181 , and the downstream side of the exhaust gas flow direction of the turbine wheel 11 is defined as a downstream exhaust gas passage 182 . and The upstream exhaust passage 181 connects the engine body 10 and the turbine wheel 11 .

In the illustrated embodiment, the bypass passage 20 connects a branch portion 183 provided in the upstream exhaust passage 181 and a confluence portion 184 provided in the downstream exhaust passage 182 as shown in FIG. there is The wastegate valve 21 is configured to open and close the bypass passage 20 . By opening the waste gate valve 21 and diverting part of the flow of the exhaust gas flowing toward the turbine wheel 11 to the bypass passage 20, the amount and thermal energy of the exhaust gas sent to the turbine wheel 11 can be reduced. As a result, the boost pressure of the combustion gas can be reduced.

(turbine housing configuration)
2 is a schematic cross-sectional view of a turbocharger with a turbine housing according to one embodiment of the present disclosure; FIG. 3 is a schematic perspective view of a turbine housing in accordance with one embodiment of the present disclosure; FIG. The schematic cross-sectional view shown in FIG. 2 is a schematic cross-sectional view corresponding to the cross section taken along line AA in FIG.
Hereinafter, as shown in FIG. 2, for example, the direction in which the axis LA of the turbine housing 3 extends is defined as the axial direction, and the side of the axial direction on which the turbine housing 3 is positioned with respect to the bearing housing 17 (right side in the drawing). is one side, and the side where the bearing housing 17 is located with respect to the turbine housing 3 (the left side in the drawing) is the other side.

The turbine housing 3 according to some embodiments includes, for example, as shown in FIG. , is equipped with

The scroll channel 40 is a channel for introducing exhaust gas from the outside of the turbine housing 3 into the wheel accommodation space 30 in which the turbine wheel 11 is accommodated, as shown in FIG. 2, for example. The wheel accommodation space 30 communicates with the scroll channel 40 and the discharge channel 50 and accommodates the turbine wheel 11 in a rotatable state. The scroll flow path 40 has a spiral shape surrounding the circumference (diameter direction outside) of the wheel housing space 30 . The scroll flow path 40 is defined by an inner wall surface 41 of the scroll flow path forming portion 4 . In other words, the scroll passage forming portion 4 has an inner wall surface 41 defining the scroll passage 40 therein.

As shown in FIG. 3 , the turbine housing 3 is formed with an exhaust gas introduction port 31 for introducing exhaust gas from the outside of the turbine housing 3 into the scroll passage 40 . In the illustrated embodiment, the exhaust gas introduction port 31 is formed at one end portion 42 of the scroll flow path forming portion 4 .

The discharge channel 50 is a channel for discharging the exhaust gas that has passed through the turbine wheel 11 to the outside of the turbine housing 3, as shown in FIG. 2, for example. The discharge channel 50 is provided on one side of the wheel housing space 30 in the axial direction. The discharge channel 50 is defined by a channel wall surface 51 that is an inner wall surface of the discharge channel forming portion 5 . In other words, the discharge channel forming portion 5 has a channel wall surface 51 defining the discharge channel 50 therein.

The turbine housing 3 is formed with an exhaust gas discharge port 32 for discharging the exhaust gas flowing through the discharge passage 50 to the outside of the turbine housing 3, as shown in FIG. 2, for example. In the illustrated embodiment, the exhaust gas discharge port 32 is formed at the end portion 52 on the one side of the discharge channel forming portion 5 .

In the illustrated embodiment, the turbine housing 3 further comprises a connecting portion 7 that connects the scroll channel forming portion 4 and the discharge channel forming portion 5, as shown in FIG. 2, for example. The connecting portion 7 includes a shroud surface 71 convexly curved so as to face the tips 112 of the turbine blades 111 of the turbine wheel 11, and a surface connected to the shroud surface 71, and an inner wall extending along the axial direction. a wall surface 72; The inner wall surface 72 includes a surface that continues to the channel wall surface 51 . In the embodiment shown in FIG. 2 , the discharge passage forming portion 5 and the connecting portion 7 are bounded by an axial position corresponding to the trailing edge 113 of the turbine blade 111 .

Exhaust gas discharged from the engine body 10 is introduced into the turbine housing 3 through an exhaust gas introduction port 31 of the turbine housing 3, passes through the scroll passage 40, and is sent to the turbine wheel 11 (wheel housing space 30). The exhaust gas sent to the turbine wheel 11 (the wheel housing space 30 ) flows through the exhaust passage 50 toward one side in the axial direction, and then is discharged from the exhaust gas discharge port 32 to the outside of the turbine housing 3 .

The turbine housing 3 includes, for example, as shown in FIG. 3 , a bypass passage forming portion 6 that forms a bypass passage 60 that bypasses the wheel housing space 30 and sends the exhaust gas from the scroll passage 40 to the exhaust passage 50 . ing. That is, the bypass passage 20 (see FIG. 1) described above is formed inside the bypass passage forming portion 6 as the bypass passage 60 .

The bypass channel 60 is defined by an inner wall surface 61 of the bypass channel forming portion 6, as shown in FIG. 3, for example. In other words, the bypass channel forming portion 6 has an inner wall surface 61 defining the bypass channel 60 therein.
An inner wall surface 41 of the scroll flow path forming portion 4 is formed with an opening 43 that allows the scroll flow path 40 and the bypass flow path 60 to communicate with each other. In the illustrated embodiment, the opening 43 is formed in the edge 44 of the inner wall surface 41 on the one end 42 side.

4 is a schematic cross-sectional view taken along line BB of FIG. 3 of a turbine housing according to an embodiment of the present disclosure; FIG. FIG. 5 is a schematic cross-sectional view of a turbine housing according to an embodiment of the present disclosure, showing a state in which wastegate valves are disposed. FIG. 6 is a schematic cross-sectional view showing a cross-section perpendicular to the axis of the turbine housing according to one embodiment of the present disclosure, and is a schematic cross-sectional view showing a state viewed from the outlet side of the discharge channel.

(Channel wall surface of discharge channel forming part, valve housing space, waste gate valve)
As shown, for example, in FIGS. 2 and 4, the flow channel wall surface 51 of the discharge flow channel forming portion 5 is formed in at least a part of the circumferential direction of the turbine housing toward the outlet side (right side in the drawing) of the discharge flow channel 50 . 3 includes an inclined surface 55 that slopes at an increasing distance with respect to axis LA. Hereinafter, the inclination angle of the inclined surface 55 with respect to the axis LA is assumed to be φ.

For example, as shown in FIGS. 4 and 5, a valve accommodation space 54 that accommodates the above-described waste gate valve 21 is formed inside the above-described discharge passage forming portion 5 . The valve accommodation space 54 is a space extending radially outward from the discharge channel 50 , and is defined by the inclined surface 55 and the valve accommodation surface 56 of the channel wall surface 51 of the discharge channel forming portion 5 . The discharge channel 50 includes a valve accommodation space 54 and a space 53 other than the valve accommodation space 54 . The space 53 is a space for causing the exhaust gas sent from the turbine wheel 11 to flow toward the exhaust gas discharge port 32 .

In the illustrated embodiment, the valve-receiving surface 56 includes a first valve-receiving surface 561 extending along a direction intersecting the inclined surface 55 and a second valve housing surface 562 extending along a direction intersecting with the first a third valve-receiving surface 563 connecting the outer edge of the valve-receiving surface 561 and the outer edge of the second valve-receiving surface 562 ; The valve-receiving space 54 described above is defined between the first valve-receiving surface 561 and the second valve-receiving surface 562 . In the embodiment shown in FIG. 4, the first valve receiving surface 561 and the second valve receiving surface 562 each extend along a radial direction. The third valve housing surface 563 extends along the axial direction.

For example, as shown in FIG. 4 , a waste gate port 62 is formed in the discharge passage forming portion 5 to allow communication between the valve housing space 54 and the bypass passage 60 . In the illustrated embodiment, the discharge passage forming portion 5 includes a protruding portion 57 that protrudes in a columnar shape from the first valve housing surface 561 , and the waste gate port 62 opens to an end surface 571 of the protruding portion 57 .

As shown in FIG. 5, for example, the wastegate valve 21 includes a valve body 211 configured to be able to close the wastegate port 62, and a valve body 211 that supports the valve body 211 and is configured to be rotatable. and a rotating portion 212 . The rotating portion 212 includes an arm 213 that is inserted through an arm insertion hole 58 that is formed in the exhaust passage forming portion 5 and that communicates the outside of the turbine housing 3 with the valve housing space 54 . A rotating device 215 for rotating the arm 213 is connected to one end portion 214 of the arm 213 protruding outside the turbine housing 3 . When the rotating device 215 rotates the arm 213 , the valve body 211 rotates in the circumferential direction of the arm 213 . The wastegate valve 21 rotates the valve body 211 to close or open the wastegate port 62 , thereby controlling the flow rate of the exhaust gas flowing from the bypass flow path 60 to the valve housing space 54 .

In a plan view of the turbine housing 3 viewed along the axis LA from the outlet side of the discharge passage 50 as shown in FIG. , including the valve-side inclined surface 551 present in the . In the illustrated embodiment, as shown in FIG. 6 , the above-described inclined surface 55 exists over the entire circumference of the channel wall surface 51 . In the plan view, the inclined surface 55 includes the valve-side inclined surface 551 and the non-valve-side inclined surface 552 that exists in a range A2 that does not overlap with the valve housing space 54 in the circumferential direction. As shown in FIG. 4, the non-valve side inclined surface 552 exists not only on the inlet side of the discharge passage 50 from the valve accommodation space 54 but also in the range where the valve accommodation space 54 exists in the axial direction. ing. In the embodiment shown in FIG. 4 , the non-valve inclined surface 552 extends from an axial position corresponding to the trailing edge 113 of the turbine blade 111 to an axial position corresponding to the inner peripheral edge 565 of the second valve receiving surface 562 . exists throughout.

(Configuration of turbine housing according to comparative example)
FIG. 7 is a schematic cross-sectional view of a turbocharger provided with a turbine housing according to a comparative example. FIG. 8 is a schematic cross-sectional view of a turbine housing according to a comparative example, taken along line BB in FIG.
As shown in FIG. 7, a turbocharger 1A according to a comparative example includes at least the turbine wheel 11 described above, the rotating shaft 13 described above, and a turbine housing 3A configured to accommodate the turbine wheel 11. there is As shown in FIG. 8, the turbocharger 1A further includes the above-described wastegate valve 21 housed in the turbine housing 3A.

As shown in FIG. 7, the turbine housing 3A according to the comparative example has a scroll flow path forming portion 4A forming the scroll flow path 40 described above and a discharge flow path 50A corresponding to the discharge flow path 50 described above. It has a discharge channel forming portion 5A and a connection portion 7A that connects the scroll channel forming portion 4A and the discharge channel forming portion 5A. The connection portion 7A includes the shroud surface 71 described above and the inner wall surface 72 described above. As shown in FIG. 8, the turbine housing 3A further includes a bypass passage forming portion 6A that forms the bypass passage 60 described above.

The discharge channel 50A is demarcated by a channel wall surface 51A of the discharge channel forming portion 5A, as shown in FIG. The flow path wall surface 51A includes an inner inner wall surface 511A including a surface connected to the inner wall surface 72 described above, and an outer inner wall surface 512A positioned radially outward of the inner inner wall surface 511A and on one side in the axial direction. , and a curved surface 513A curved concavely toward the other side in the axial direction so as to connect the inner inner wall surface 511A and the outer inner wall surface 512A. Each of the inner inner wall surface 511A and the outer inner wall surface 512A extends in the axial direction, and the inlet side (left side in the figure) and the outlet side (right side in the figure) of the discharge passage 50 are separated from the axis LA. the distances are equal.

The channel wall surface 51A further includes a valve housing surface 56A, as shown in FIG. The valve housing surface 56A includes the above-described first valve housing surface 561, the above-described second valve housing surface 562, and the above-described third valve housing surface 563. The discharge passage 50A is a valve accommodation space 54A in which the waste gate valve 21 described above is accommodated, and includes a valve accommodation space 54A defined by a valve accommodation surface 56A and a space 53A other than the valve accommodation space 54A. .

(Comparison between an embodiment of the present disclosure and a comparative example)
FIG. 9 is a diagram for explaining pressure distribution of exhaust gas in a turbine housing according to an embodiment of the present disclosure; FIG. 10 is a diagram for explaining pressure distribution of exhaust gas in a turbine housing according to a comparative example. FIG. 11 is a diagram for explaining pressure distribution of exhaust gas in a turbine housing according to an embodiment of the present disclosure; FIG. 12 is a diagram for explaining pressure distribution of exhaust gas in a turbine housing according to a comparative example. In FIGS. 9 to 12, the portions where the pressure of the exhaust gas is high are shown dark, and the portions where the pressure of the exhaust gas is low are shown light. 9 and 10 show simulation results under high pressure ratio conditions, where the pressure ratio of the turbocharger is 1.5 and the speed ratio U/Co is 0.56. 11 and 12 show the simulation results under lower pressure ratio conditions compared to FIGS. 9 and 10 where the pressure ratio of the turbocharger is 1.2 and the speed ratio U/Co is 0.51. Here, the speed ratio U/Co is represented by the ratio between the turning speed U of the turbine blade 111 and the theoretical adiabatic speed Co. The theoretical adiabatic velocity Co indicates the maximum flow velocity at which the exhaust gas is accelerated from the turbine inlet temperature and pressure ratio.

In the turbocharger 1A according to the comparative example, as shown in FIGS. 10 and 12, the exhaust gas that has flowed from the turbine wheel 11 (the wheel housing space 30) into the discharge passage 50A travels axially along the inner wall surface 511A. Since it flows toward one side of the direction, it is difficult to generate a flow toward the outer inner wall surface 512A and the valve housing surface 56A located radially outward. In addition, pressure loss is large between the inner inner wall surface 511A and the outer inner wall surface 512A, and between the inner inner wall surface 511A and the valve accommodating surface 56A, because the passage area is rapidly expanded. becomes.

On the other hand, in the turbocharger 1, as shown in FIGS. 9 and 11, the exhaust gas that has flowed from the turbine wheel 11 (the wheel housing space 30) into the discharge passage 50 flows into the above-described inclined surface 55 (the valve-side inclined surface). 551 and the non-valve-side inclined surface 552), the flow toward the outer inner wall surface 512A and the valve housing surface 56A positioned radially outward is It can be generated immediately from the vicinity of the inlet side of the discharge channel 50 . Also, between the inlet side and the outlet side of the non-valve side inclined surface 552, the expansion ratio of the flow passage area should be suppressed compared to the gap between the inner inner wall surface 511A and the outer inner wall surface 512A of the turbocharger 1A. Therefore, pressure loss can be suppressed. In addition, the expansion ratio of the passage area between the valve-side inclined surface 551 and the valve housing surface 56 can be suppressed compared to the area between the inner inner wall surface 511A of the turbocharger 1A and the valve housing surface 56A. , pressure loss can be suppressed.

As shown in FIGS. 9 and 10, the simulation results under high pressure ratio conditions show that the turbocharger 1 has improved static pressure recovery coefficient and diffuser efficiency compared to the turbocharger 1A according to the comparative example. Also, in the simulation results under low pressure ratio conditions, as shown in FIGS. 11 and 12, the static pressure recovery coefficient and the diffuser efficiency of the turbocharger 1 were improved compared to the turbocharger 1A according to the comparative example. .

In some embodiments, the inclined surface 55 (valve-side inclined surface 551) described above in a plan view of the turbine housing 3 viewed along the axis LA from the outlet side of the discharge passage 50 as shown in FIG. exists in a range A1 that overlaps with the valve housing space 54 in the circumferential direction.

According to the above configuration, the flow path wall surface 51 of the discharge flow path forming portion 5 is arranged such that the distance from the axis LA of the turbine housing 3 increases toward the outlet side of the discharge flow path 50 in at least a part of the circumferential direction. It includes an inclined surface 55 which is inclined to . The inclined surface 55 exists in a range A1 that overlaps the valve housing space 54 in the circumferential direction in a plan view of the turbine housing 3 along the axis LA. Therefore, the outlet side of the discharge passage 50 is gently expanded compared to the inlet side at least on the valve side in the circumferential direction due to the inclined surface 55 existing in the overlapping range A1. have a shape. Such a discharge passage 50 can improve the static pressure recovery effect by reducing the flow velocity of the exhaust gas flowing toward the outlet side at least on the valve side in the circumferential direction to suppress the pressure loss. By improving the static pressure recovery effect in the discharge passage 50, the performance of the turbocharger 1 can be improved.

In addition, according to the above configuration, the outlet side of the discharge channel 50 has a shape in which the channel is gently enlarged compared to the inlet side due to the inclined surface 55 existing at least in the overlapping range A1. there is Therefore, access to the valve housing space 54 is facilitated, and the mountability of the wastegate valve 21 can be improved.

As shown in FIG. 6, in a plan view of the turbine housing 3 along the axis LA and viewed from the outlet side of the discharge passage 50, a reference line RL passing through the axis LA and the center C of the waste gate port 62 described above. and the flow path wall surface 51 of the discharge flow path forming portion 5, the position of the intersection point P1 on the side closer to the waste gate port 62 is the 0° position, and the clockwise rotation around the axis LA is the positive direction. and the circumferential angle in the positive direction with respect to the 0° position is defined as θ.

In some embodiments, as shown in FIG. 6, the aforementioned inclined surface 55 (valve-side inclined surface 551) exists at least in the range of −45°≦θ≦45°.
In the illustrated embodiment, the valve-side inclined surface 551 is defined by a point P3 on the flow path wall surface 51 and the axis LA in a plan view of the turbine housing 3 along the axis LA and viewed from the outlet side of the discharge flow path 50. A region between the connecting line segment and the line segment connecting the point P4 on the flow path wall surface 51 and the axis LA, on the valve side (the side where the center C of the waste gate port 62 is located with respect to the axis LA) exists in the above-described range A1, which is the region of . In the embodiment shown in FIG. 6, the point P3 lies in the range of 270°<θ<315° and the point P4 lies in the range of 45°<θ<90°.

In the illustrated embodiment, the non-valve side sloping surface 552 is defined by a point P3 on the flow path wall surface 51 and the axis LA in a plan view of the turbine housing 3 along the axis LA and viewed from the outlet side of the discharge flow path 50. and the line segment connecting the point P4 on the flow passage wall surface 51 and the axis LA, on the non-valve side (opposite to the side where the center C of the waste gate port 62 is located with respect to the axis LA side) exists in the range A2 described above. The non-valve side inclined surface 552 exists in at least the range of 135°≦θ≦225°.

In the illustrated embodiment, the non-valve-side inclined surface 552 has an arcuate contour shape centered on the axis LB in a plan view of the turbine housing 3 along the axis LA and viewed from the outlet side of the discharge passage 50. is formed in The axis LB is positioned closer to the bulb than the axis LA and extends in a direction parallel to the axis LA. The valve-side inclined surface 551 is configured to have a longer distance from the axis LB than the non-valve-side inclined surface 552 in plan view.

According to the above configuration, the discharge flow path 50 is at least centered C , the outlet side of the discharge channel 50 has a shape in which the channel is gradually expanded compared to the inlet side. At least on the valve side including the center C of the waste gate port 62 in the circumferential direction, the discharge passage 50 reduces the flow velocity of the exhaust gas flowing toward the outlet side to suppress the pressure loss, thereby recovering the static pressure. You can improve the effect.

In some embodiments, as shown in FIG. 6, the above-described inclined surface 55 is formed on the flow path wall surface 51 in a plan view of the turbine housing 3 along the axis LA from the outlet side of the discharge flow path 50. It exists all around. When the average inclination angle of the inclined surface 55 existing in the range of −90°<θ≦90° is φ1, and the average inclination angle of the inclined surface 55 existing in the range of 90°<θ≦270° is φ2. , the relationship φ1>φ2 is satisfied.

In the illustrated embodiment, the inclination angle φ of the inclined surface 55 is maximum when θ=0°, and the inclination angle φ gradually decreases toward the positive direction or the negative direction in the circumferential direction, and θ=225°. The inclination angle φ of the inclined surface 55 is the minimum at 1°.

According to the above configuration, the inclined surface 55 exists over the entire circumference of the flow path wall surface 51 in the plan view. In the turbine housing 3 having such an inclined surface 55, the exhaust gas flowing through the exhaust passage 50 spreads along the valve-side inclined surface 55 and the non-valve-side inclined surface 55, thereby By reducing the flow velocity of the exhaust gas flowing through the exhaust passage 50, the static pressure recovery effect in the discharge passage 50 can be improved. In addition, according to the above configuration, since the valve-side inclined surface 55 is steeper than the non-valve-side inclined surface 55, the exhaust gas flowing along the valve-side inclined surface 55 is allowed to pass through a wide space. The static pressure recovery effect in the discharge passage 50 can be further improved because the static pressure can be expanded in the valve accommodation space 54 by being guided to the valve accommodation space 54 .

Further, according to the above configuration, the inclined surface 55 on the valve side is steeper than the inclined surface 55 on the non-valve side. Since the turbine housing 3 having such an inclined surface 55 can increase the volume of the discharge passage 50 on the valve side, it is possible to improve the mountability of the waste gate valve 21 .

In some embodiments, the inclination angle φ of the inclined surface 55 described above is configured to be maximum in the range of −45°≦θ≦45°. In this case, the inclination angle φ of the inclined surface 55 is configured to be maximum in the range of −45°≦θ≦45°, that is, in the valve-side range A1 including the center C of the waste gate port 62. . The turbine housing 3 having such an inclined surface 55 guides the exhaust gas flowing along the valve-side inclined surface 55 including the center C of the wastegate port 62 to the valve accommodation space 54 having a large space, thereby Since it can be expanded at 54, the static pressure recovery effect in the discharge channel 50 can be effectively improved.

In some embodiments, as shown in FIG. 4, the above-described channel wall surface 51 extends along the direction intersecting the inclined surface 55 (valve-side inclined surface 551). A second valve housing surface 562 extending along a direction intersecting the housing surface 561 and the inclined surface 55 (valve-side inclined surface 551 ), and extending from the wheel housing space 30 rather than the first valve housing surface 561 . and the aforementioned second valve receiving surface 562 that is spaced apart and defines the valve receiving space 54 therebetween. The inclination angle of an imaginary line IL passing through the inner peripheral edge portion 564 of the first valve accommodating surface 561 and the inner peripheral edge portion 565 of the second valve accommodating surface 562 with respect to the axis LA is assumed to be α. In a plan view of the turbine housing 3 along the axis LA, as shown in FIG. 6, the average inclination angle of the inclined surface 55 (the valve-side inclined surface 551) in the circumferential range A1 in which the valve housing space 54 exists. is φ3. The inclination angle α described above satisfies the relationship α=φ3±5°.

According to the above configuration, the inclination angle α satisfies the relationship α=φ3±5°. The turbine housing 3 that satisfies the above relationship can guide the exhaust gas flowing along the inclined surface 55 (valve-side inclined surface 551) in the range A1 so as to spread radially outward along the imaginary line IL. As shown in FIG. 11, the turbine housing 3 that satisfies the above relationship can guide the flow of the exhaust gas even if the exhaust gas flows through the discharge passage 50 at a low speed. can be effectively improved.

In some embodiments, the inclination angle φ of the inclined surface 55 described above satisfies the condition of 0°<φ<30°. If the inclination angle φ of the inclined surface 55 is 0°, the pressure recovery effect in the discharge passage 50 may be small. Further, when the inclination angle φ of the inclined surface 55 is a steep angle of 30° or more, the exhaust gas flowing through the discharge passage 50 separates from the inclined surface 55 with the steep inclination angle φ, and the inclined surface 55 There is a possibility that the flow of the exhaust gas facing the exhaust flow path 50 may become poor, and the pressure recovery effect in the discharge flow path 50 may deteriorate. According to the above configuration, the inclination angle φ of the inclined surface 55 satisfies the condition of 0°<φ<30°. The pressure recovery effect in the channel 50 can be improved.

In one embodiment, the inclination angle φ of the inclined surface 55 described above satisfies the condition of 0°<φ<25°. In this case, separation of the exhaust gas from the inclined surface 55 can be more effectively suppressed, so the pressure recovery effect in the discharge passage 50 can be improved.
Further, in one embodiment, the inclination angle φ of the inclined surface 55 described above satisfies the condition of 10°<φ<30°. In this case, since the inclination angle φ is 10° or more, it is possible to more effectively suppress the decrease in the pressure recovery effect in the discharge channel 50, thereby improving the pressure recovery effect in the discharge channel 50. can be made
Further, in one embodiment, the inclination angle φ of the inclined surface 55 described above satisfies the condition of 10°<φ<25°. In this case, the pressure recovery effect in the discharge channel 50 is reduced, and separation of the exhaust gas from the inclined surface 55 can be suppressed, so the pressure recovery effect in the discharge channel 50 can be improved.

In some embodiments, for example, as shown in FIG. 2 , the outer wall surface 59 of the discharge passage forming portion 5 described above extends at least partially along the inclination direction of the inclined surface 55 in the circumferential direction. there is In the illustrated embodiment, the outer wall surface 59 is a surface formed on the opposite side of the inclined surface 55 (the non-valve side inclined surface 552) in the thickness direction, and is present in at least the range A2 in the circumferential direction. ing.

According to the above configuration, at least a portion of the outer wall surface 59 of the discharge passage forming portion 5 in the circumferential direction extends along the inclination direction of the inclined surface 55 . In this case, since at least a part of the discharge passage forming portion 5 in the circumferential direction can be formed into a conical cylindrical shape, the outer wall surface 59 can be formed more easily than in the case where the discharge passage forming portion 5 has a cylindrical shape. Surface area (heat radiation area) can be reduced. By reducing the surface area of the outer wall surface 59 of the exhaust passage forming portion 5, the turbine housing 3 can suppress heat energy loss due to heat radiation from the turbine housing 3, thereby improving the performance of the turbocharger 1. can be made

In some embodiments, for example, as shown in FIG. 2, the above-described turbine housing 3 includes the above-described scroll passage-forming portion 4, the above-described discharge passage-forming portion 5, and the scroll passage-forming portion 4. and the above-described connecting portion 7 that connects with the discharge flow path forming portion 5 . As shown in FIG. 2, the connecting portion 7 has a groove portion 8 that is recessed toward the upstream side (left side in the drawing) in the direction in which the axis LA extends in at least a part of the outer wall surface 73 in the circumferential direction. curved like a

In the illustrated embodiment, as shown in FIG. 2 , the outer wall surface 73 includes a first outer wall surface 731 located on the opposite side of the inner wall surface 72 of the connecting portion 7 in the thickness direction, and a first outer wall surface 731 . and a second outer wall surface 732 provided at a position opposite to the outer wall surface 732 and having one axial side extending radially outward from the other axial side. The first outer wall surface 731 includes a surface that is loosely connected to the outer wall surface 59 of the discharge channel forming portion 5 . The groove portion 8 is defined by a first outer wall surface 731 and a second outer wall surface 732 .

According to the above configuration, the connecting portion 7 that connects the scroll flow path forming portion 4 and the discharge flow path forming portion 5 is provided on at least a part of the outer wall surface 73 in the circumferential direction, and on the upstream side in the direction in which the axis LA extends. Since it is curved so as to form the groove portion 8 that is recessed toward it, it is possible to suppress the transfer of heat from the scroll flow path forming portion 4 to the discharge flow path forming portion 5 . By suppressing the heat transfer from the scroll flow path forming portion 4 to the discharge flow path forming portion 5, it is possible to suppress the loss of thermal energy due to the heat radiation from the discharge flow path forming portion 5. It can improve performance.

The turbocharger 1 according to some embodiments, for example, as shown in FIG. 1, can open and close the above-described turbine wheel 11, the above-described turbine housing 3, and the above-described bypass passage 60 (bypass passage 20). and the waste gate valve 21 configured as described above.

According to the above configuration, the exhaust passage 50 of the turbine housing 3 has a shape in which the outlet side of the exhaust passage 50 is gently enlarged compared to the inlet side at least on the valve side in the circumferential direction due to the inclined surface 55 . have. Such a discharge passage 50 can improve the static pressure recovery effect by reducing the flow velocity of the exhaust gas flowing toward the outlet side at least on the valve side in the circumferential direction to suppress the pressure loss. By improving the static pressure recovery effect in the discharge passage 50, the performance of the turbocharger 1 can be improved.

The present disclosure is not limited to the above-described embodiments, and includes modifications of the above-described embodiments and modes in which these modes are combined as appropriate.

The contents described in the several embodiments described above are understood as follows, for example.

(1) A turbine housing (3) according to at least one embodiment of the present disclosure comprising:
A turbine housing (3) configured to house a turbine wheel (11) and a wastegate valve (21), comprising:
a scroll passage forming portion (4) for forming a scroll passage (40) for introducing exhaust gas from the outside of the turbine housing (3) into a wheel accommodation space (30) in which the turbine wheel (11) is accommodated; ,
a discharge passage forming portion (5) forming a discharge passage (50) for discharging the exhaust gas that has passed through the turbine wheel (11) to the outside of the turbine housing (3);
a bypass flow path forming portion (6) forming a bypass flow path (60) that bypasses the wheel housing space (30) from the scroll flow path (40) and sends the exhaust gas to the discharge flow path (50); with
A valve accommodation space (54) for accommodating the waste gate valve (21) is formed inside the discharge passage forming part (5),
The flow path wall surface (51) of the discharge flow path forming part (5) has, in at least a part of its circumferential direction, a distance from the axis (LA) of the turbine housing toward the outlet side of the discharge flow path (50). includes a sloping surface (55) sloping such that the
The inclined surface (55) exists in a range (A1) that overlaps the valve housing space (54) in the circumferential direction in a plan view of the turbine housing along the axis (LA).

According to the above configuration (1), the flow path wall surface of the discharge flow path forming portion is inclined at least partially in the circumferential direction so that the distance from the axis of the turbine housing increases toward the outlet side of the discharge flow path. It contains an inclined surface that The inclined surface exists in a range that overlaps the valve housing space in the circumferential direction in a plan view of the turbine housing along the axis. For this reason, the discharge channel has a shape in which the outlet side of the discharge channel is gently expanded compared to the inlet side at least on the valve side in the circumferential direction due to the inclined surfaces existing in the overlapping range. are doing. Such a discharge channel can improve the static pressure recovery effect by reducing the flow velocity of the exhaust gas flowing toward the outlet side at least on the valve side in the circumferential direction to suppress the pressure loss. By improving the static pressure recovery effect in the discharge passage, the performance of the turbocharger can be improved.

(2) In some embodiments, the turbine housing of (1) above,
A waste gate port (62) for communicating the valve housing space (54) and the bypass flow path (60) is formed in the discharge flow path forming portion (5),
In a plan view of the turbine housing along the axis (LA), a reference line (RL) passing through the axis (LA) and the center (C) of the waste gate port, and the position of the discharge passage forming portion. Of the points of intersection (P1, P2) with the wall surface of the flow path, the position of the intersection (P1) on the side closer to the waste gate port is the 0° position, and the clockwise direction around the axis is the positive direction. When the angle of the circumferential direction in the positive direction with respect to the ° position is θ,
The inclined surface (55) exists in at least the range of -45°≤θ≤45°.

According to the above configuration (2), the discharge flow passage is configured to discharge at least on the side of the valve including the center of the waste gate port in the circumferential direction by the inclined surface existing in the range of at least -45° ≤ θ ≤ 45°. The outlet side of the flow path has a shape in which the flow path is gently expanded compared to the inlet side. At least on the side of the valve that includes the center of the wastegate port in the circumferential direction, such a discharge channel reduces the flow velocity of the exhaust gas flowing toward the outlet side to suppress pressure loss, thereby improving the static pressure recovery effect. can be made

(3) In some embodiments, the turbine housing of (2) above, comprising:
The inclined surface (55) exists along the entire circumference of the flow path wall surface (51) in a plan view of the turbine housing along the axis,
φ1 is the average inclination angle of the inclined surfaces present in the range of −90°<θ≦90°,
If φ2 is the average inclination angle of the inclined surfaces existing in the range of 90°<θ≦270°, the relationship φ1>φ2 is satisfied.

According to the configuration (3) above, the inclined surface exists along the entire circumference of the flow channel wall surface in the plan view. In the turbine housing having such an inclined surface, the exhaust gas flowing through the exhaust passage spreads along the valve-side inclined surface and the non-valve-side inclined surface, thereby reducing the flow velocity of the exhaust gas flowing through the exhaust passage. can be reduced to improve the static pressure recovery effect in the discharge channel. Further, according to the above configuration, since the inclined surface on the valve side is steeper than the inclined surface on the non-valve side, the exhaust gas flowing along the inclined surface on the valve side can be accommodated in the valve with a wide space. Since it can be guided into the space and expanded in the valve accommodation space, the static pressure recovery effect in the discharge passage can be further improved.

(4) In some embodiments, the turbine housing of (3) above, comprising:
The inclination angle (φ) of the inclined surface (55) is configured to be maximized in the range of −45°≦θ≦45°.

According to the configuration (4) above, the inclination angle of the inclined surface is maximized in the range of −45°≦θ≦45°, that is, in the valve side range including the center of the wastegate port. . The turbine housing having such an inclined surface can guide the exhaust gas flowing along the inclined surface on the valve side including the center of the waste gate port to the valve accommodating space having a wide space, and expand it in the valve accommodating space. Therefore, the static pressure recovery effect in the discharge channel can be effectively improved.

(5) In some embodiments, the turbine housing according to any one of (2) to (4) above,
The channel wall surface (51) is
a first valve housing surface (561) extending along a direction intersecting the inclined surface (55);
A second valve housing surface (562) extending along a direction intersecting the inclined surface (55) and located farther from the wheel housing space (30) than the first valve housing surface. a second valve-receiving surface (562) formed and defining said valve-receiving space (54) with said first valve-receiving surface;
including
The angle of inclination of the imaginary line (IL) passing through the inner peripheral edge (563) of the first valve housing surface and the inner peripheral edge (564) of the second valve housing surface with respect to the axis (LA) is α,
When the average inclination angle of the inclined surface (55) in the circumferential range in which the valve accommodating space (54) exists in a plan view of the turbine housing along the axis is φ3, α= It satisfies the relationship of φ3±5°.

According to the configuration (5) above, the relationship α=φ3±5° is satisfied. The turbine housing that satisfies the above relationship can guide the exhaust gas flowing along the inclined surface in the above range so as to spread radially outward along the imaginary line. A turbine housing that satisfies the above relationship can guide the flow of exhaust gas even if the exhaust gas flowing through the exhaust passage is at a low speed, so that the static pressure recovery effect in the exhaust passage can be effectively improved.

(6) In some embodiments, the turbine housing according to any one of (1) to (5) above,
The condition of 0°<φ<30° is satisfied, where φ is the inclination angle of the inclined surface (55) with respect to the axis (LA).

If the inclination angle φ of the inclined surface is 0°, there is a possibility that the pressure recovery effect in the discharge channel may be small. Further, when the inclination angle φ of the inclined surface is a steep angle of 30° or more, the exhaust gas flowing through the discharge channel separates from the inclined surface with the steep inclination angle φ, and the exhaust gas faces the inclined surface. flow may become poor and the pressure recovery effect in the discharge channel may be reduced. According to the above configuration (6), since the inclination angle φ of the inclined surface satisfies the condition of 0°<φ<30°, it is possible to improve the flow of the exhaust gas facing the inclined surface. It is possible to improve the pressure recovery effect in the flow path.

(7) In some embodiments, the turbine housing according to any one of (1) to (6) above,
At least a part of the outer wall surface (59) of the discharge channel forming part (5) extends along the inclination direction of the inclined surface (55) in the circumferential direction.

According to the above configuration (7), at least a part of the outer wall surface of the discharge passage forming portion in the circumferential direction extends along the inclination direction of the inclined surface. In this case, since at least a portion of the discharge channel forming portion in the circumferential direction can be formed into a conical cylindrical shape, the surface area of the outer wall surface (heat dissipation area) can be reduced. By reducing the surface area of the outer wall surface of the exhaust passage forming portion of the turbine housing, the loss of heat energy due to heat radiation from the turbine housing can be suppressed, so that the performance of the turbocharger can be improved.

(8) In some embodiments, the turbine housing according to any one of (1) to (7) above,
The turbine housing (3) further includes a connecting portion (7) that connects the scroll flow path forming portion (4) and the discharge flow path forming portion (5),
The connection portion (7) is formed with a groove portion (8) recessed toward the upstream side in the direction in which the axis (LA) extends in at least a part of the outer wall surface (73) in the circumferential direction. curved.

According to the above configuration (8), the connecting portion that connects the scroll flow path forming portion and the discharge flow path forming portion is provided on at least a part of the outer wall surface in the circumferential direction toward the upstream side in the direction in which the axis extends. Since it is curved so as to form a recessed groove, it is possible to suppress the transfer of heat from the scroll flow path forming portion to the discharge flow path forming portion. By suppressing the heat transfer from the scroll channel forming portion to the exhaust channel forming portion, it is possible to suppress the loss of thermal energy due to the heat radiation from the exhaust channel forming portion, thereby improving the performance of the turbocharger. be able to.

(9) A turbocharger (1) according to at least one embodiment of the present disclosure,
a turbine wheel (11);
a turbine housing (3) according to any one of (1) to (8);
and a waste gate valve (21) configured to open and close the bypass channel.

According to the above configuration (9), the exhaust passage of the turbine housing has a shape in which the outlet side of the exhaust passage is gently enlarged compared to the inlet side at least on the valve side in the circumferential direction due to the inclined surface. have. Such a discharge channel can improve the static pressure recovery effect by reducing the flow velocity of the exhaust gas flowing toward the outlet side at least on the valve side in the circumferential direction to suppress the pressure loss. By improving the static pressure recovery effect in the discharge passage, the performance of the turbocharger can be improved.

1, 1A turbocharger 3, 3A turbine housing 30 wheel accommodation space 31 exhaust gas introduction port 32 exhaust gas discharge port 4, 4A scroll channel forming portion 40 scroll channel 41 inner wall surface 42 one end portion 43 opening 5 discharge channel forming portion 50, 50A discharge channel 51, 51A channel wall surface 511A inner inner wall surface 512A outer inner wall surface 513A curved surface 52 end portions 53, 53A space 54, 54A valve housing space 55 inclined surface 551 valve side inclined surface 552 non-valve side inclined surface 56, 56A valve housing surface 561 first valve housing surface 562 second valve housing surface 563 third valve housing surface 564, 565 inner peripheral edge portion 57 raised portion 571 end surface 58 arm insertion hole 59 outer wall surface 6, 6A bypass passage forming portion 60 bypass flow path 61 inner wall surface 62 waste gate port 7, 7A connecting portion 71 shroud surface 72 inner wall surface 73 outer wall surface 731 first outer wall surface 732 second outer wall surface 8 groove 10 engine body 11 turbine wheel 111 turbine blade 112 tip 113 rear Rim 12 Compressor wheel 13 Rotating shaft 14 Housing 15 Bearing 16 Compressor housing 17 Bearing housing 18 Exhaust passage 181 Upstream exhaust passage 182 Downstream exhaust passage 183 Branch portion 184 Merging portion 19 Intake passage 20 Bypass passage 21 Waste gate valve 211 Valve element 212 Rotating part 213 Arm 214 One end 215 Rotating device A1, A2 Range C Center IL Virtual line LA, LB Axis line P1, P2 Intersection point P3, P4 Point RL Reference line

Claims (9)

A turbine housing configured to house a turbine wheel and a wastegate valve, comprising:
a scroll passage forming portion for forming a scroll passage for introducing exhaust gas from the outside of the turbine housing into a wheel accommodation space in which the turbine wheel is accommodated;
a discharge channel forming portion that forms a discharge channel for discharging the exhaust gas that has passed through the turbine wheel to the outside of the turbine housing;
a bypass passage forming portion that forms a bypass passage that bypasses the wheel housing space from the scroll passage and sends the exhaust gas to the discharge passage;
A valve housing space for housing the waste gate valve is formed inside the discharge passage forming portion,
The flow path wall surface of the discharge flow path forming portion is at least partially inclined in the circumferential direction such that the distance from the axis of the turbine housing increases toward the outlet side of the discharge flow path , and the a valve housing surface defining the valve housing space together with the inclined surface ;
The inclined surface includes a valve-side inclined surface that overlaps with the valve housing space in the circumferential direction in a plan view of the turbine housing along the axis,
The valve housing surface is a first valve housing surface extending along a direction intersecting the valve-side inclined surface, and is formed with a waste gate port that communicates the valve housing space and the bypass flow path. a first valve-receiving surface with a
The first valve housing surface and the valve-side inclined surface are connected at an inner peripheral edge portion of the first valve housing surface.
turbine housing. A turbine housing configured to house a turbine wheel and a wastegate valve, comprising:
a scroll passage forming portion for forming a scroll passage for introducing exhaust gas from the outside of the turbine housing into a wheel accommodation space in which the turbine wheel is accommodated;
a discharge channel forming portion that forms a discharge channel for discharging the exhaust gas that has passed through the turbine wheel to the outside of the turbine housing;
a bypass passage forming portion that forms a bypass passage that bypasses the wheel housing space from the scroll passage and sends the exhaust gas to the discharge passage;
A valve housing space for housing the waste gate valve is formed inside the discharge passage forming portion,
the flow path wall surface of the discharge flow path forming portion includes, in at least a part of its circumferential direction, an inclined surface that is inclined so that the distance from the axis of the turbine housing increases toward the outlet side of the discharge flow path;
The inclined surface exists in a range that overlaps with the valve housing space in the circumferential direction in a plan view of the turbine housing along the axis, and
A waste gate port is formed in the discharge passage forming portion for communicating the valve housing space and the bypass passage,
In a plan view of the turbine housing along the axis, among the intersections of a reference line passing through the axis and the center of the waste gate port and the flow path wall surface of the discharge flow path forming portion, the waste When the position of the intersection on the side closer to the gate port is the 0° position, the clockwise rotation around the axis is the positive direction, and the angle of the circumferential direction in the positive direction with respect to the 0° position is θ,
The inclined surface exists in a range of at least -45° ≤ θ ≤ 45°
turbine housing. The inclined surface extends along the entire periphery of the flow path wall surface in a plan view of the turbine housing along the axis,
φ1 is the average inclination angle of the inclined surface existing in the range of −90°<θ≦90°,
3. The turbine housing according to claim 2, wherein a relationship of φ1>φ2 is satisfied, where φ2 is the average inclination angle of the inclined surfaces present in the range of 90°<θ≦270°. 4. The turbine housing according to claim 3, wherein an inclination angle of said inclined surface is maximized in a range of -45°≤θ≤45°. The flow channel wall surface is
a first valve housing surface extending along a direction intersecting the inclined surface;
A second valve housing surface extending along a direction intersecting the inclined surface, the second valve housing surface being formed at a position further from the wheel housing space than the first valve housing surface, and a second valve-receiving surface defining the valve-receiving space therebetween;
including
α is the inclination angle of an imaginary line passing through the inner peripheral edge of the first valve housing surface and the inner peripheral edge of the second valve housing surface with respect to the axis;
In a plan view of the turbine housing along the axis, where φ3 is the average inclination angle of the inclined surface in the circumferential range where the valve housing space exists, α=φ3±5°. 5. A turbine housing as claimed in any one of claims 2 to 4, wherein: The turbine housing according to any one of claims 1 to 5, wherein a condition of 0°<φ<30° is satisfied, where φ is an inclination angle of the inclined surface with respect to the axis. The turbine housing according to any one of claims 1 to 6, wherein at least a portion of the outer wall surface of the discharge passage forming portion in the circumferential direction extends along the inclination direction of the inclined surface. The turbine housing further includes a connecting portion that connects the scroll flow path forming portion and the discharge flow path forming portion,
8. The connecting portion is curved such that a groove recessed toward an upstream side in a direction in which the axis extends is formed in at least a part of the outer wall surface in the circumferential direction of the connecting portion. 2. A turbine housing according to claim 1. a turbine wheel;
A turbine housing according to any one of claims 1 to 8;
and a waste gate valve configured to open and close the bypass flow path.

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