WO2024201959A1

WO2024201959A1 - Variable nozzle device, turbine, and turbocharger

Info

Publication number: WO2024201959A1
Application number: PCT/JP2023/013411
Authority: WO
Inventors: 航介内海; 永護加藤
Original assignee: 三菱重工エンジン＆ターボチャージャ株式会社
Priority date: 2023-03-30
Filing date: 2023-03-30
Publication date: 2024-10-03

Abstract

This variable nozzle device is stored in a housing together with a turbine wheel, the variable nozzle device comprising: a nozzle mount; at least one nozzle support configured such that one side thereof is supported by the nozzle mount, and the other side thereof abuts another member; and a biasing member configured to bias the nozzle mount toward the other member side. The nozzle mount and the at least one nozzle support are supported between the other member and the biasing member in the axial direction by a biasing force of the biasing member, and the at least one nozzle support includes an abutting surface that abuts the other member, and a curved surface having an inner edge connected to an outer edge of the abutting surface, and having a contour shape curved to protrude toward a direction away from the center axis of the nozzle support.

Description

Variable nozzle device, turbine and turbocharger

This disclosure relates to a variable nozzle device, and a turbine and turbocharger equipped with the variable nozzle device.

Turbochargers that use the energy of exhaust gas from an internal combustion engine to supercharge the intake air of the engine are known to include a variable geometry turbine (see, for example, Patent Document 1). A variable geometry turbine has multiple nozzle vanes arranged in the circumferential direction of the turbine wheel in an exhaust gas flow path that sends exhaust gas from the scroll flow path of the turbine to the turbine wheel, and the blade angle of these nozzle vanes can be changed from the outside by an actuator to adjust the flow path cross-sectional area of the exhaust gas flow path (flow path between adjacent nozzle vanes). A variable geometry turbine adjusts the flow path cross-sectional area of the exhaust gas flow path to change the flow speed and pressure of the exhaust gas led to the turbine wheel, thereby enhancing the supercharging effect.

Patent Document 1 discloses a nozzle support that is fixed to one of two annular plate members (nozzle mount, nozzle plate) that form an exhaust gas flow path and abuts against the other.

U.S. Pat. No. 8,684,678

In the invention described in Patent Document 1, the high-temperature exhaust gas flowing through the exhaust gas flow path causes thermal deformation of the two annular plate members, and the difference in thermal deformation of the two annular plate members causes relatively high stress between the nozzle support and the annular plate member with which the nozzle support abuts, which may cause the nozzle support to break or be damaged.

In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a variable nozzle device that can reduce stress generated between a nozzle support and another member with which the nozzle support abuts, and a turbine and turbocharger that include the variable nozzle device.

A variable nozzle device according to at least one embodiment of the present disclosure includes:
A variable nozzle device accommodated together with a turbine wheel in a housing,
A nozzle mount,
At least one nozzle support, one side of which is supported by the nozzle mount and the other side of which is configured to abut against another member;
a biasing member configured to bias the nozzle mount toward the other member,
the nozzle mount and the at least one nozzle support are supported between the other member and the biasing member in the axial direction by a biasing force of the biasing member,
The at least one nozzle support comprises:
a contact surface that contacts the other member;
a curved surface having an inner edge connected to an outer edge of the abutment surface, the curved surface having a contour shape that is convexly curved in a direction away from the central axis of the nozzle support.

A turbine according to at least one embodiment of the present disclosure includes:
The variable nozzle device;
The turbine wheel;
and a housing that houses the turbine wheel and the variable nozzle device.

A turbocharger according to at least one embodiment of the present disclosure includes:
The turbine;
and a centrifugal compressor configured to be driven by the turbine.

At least one embodiment of the present disclosure provides a variable nozzle device that can reduce stress between a nozzle support and another member with which the nozzle support abuts, and a turbine and turbocharger that include the variable nozzle device.

1 is a schematic diagram of an internal combustion engine system including a turbocharger and an internal combustion engine according to an embodiment of the present disclosure. 1 is a schematic cross-sectional view of a turbine along its axis according to an embodiment of the present disclosure; FIG. 1 is a schematic diagram of a variable nozzle device according to an embodiment of the present disclosure viewed from one side in the axial direction. FIG. 1 is a schematic cross-sectional view taken along an axis of a variable nozzle device according to an embodiment of the present disclosure. 7 is an explanatory diagram for explaining thermal deformation of a variable nozzle device according to a comparative example. FIG. 1 is an explanatory diagram for explaining thermal deformation of a variable nozzle device according to an embodiment of the present disclosure. FIG. 1 is a schematic cross-sectional view of a turbine along its axis according to an embodiment of the present disclosure; FIG.

Below, several embodiments of the present disclosure will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described as the embodiments or shown in the drawings are not intended to limit the scope of the present disclosure and are merely illustrative examples.

(Turbocharger)
FIG. 1 is a schematic diagram of an internal combustion engine system 10 including a turbocharger (supercharger) 1 and an internal combustion engine (engine) 11 according to an embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view along an axis line LA of a turbine 12 according to an embodiment of the present disclosure. The turbine 12 according to the present disclosure can be mounted on, for example, a turbocharger (supercharger) 1 for automobiles, ships, or industries (for example, for land-based power generation). In the following embodiment, the turbine 12 mounted on the turbocharger 1 will be described as an example, but the turbine 12 according to the present disclosure is not limited to being mounted on the turbocharger 1. In addition, the working fluid of the turbine 12 does not need to be limited to exhaust gas. In other words, the turbine 12 according to the present disclosure may be configured as a single turbine 12 or may be configured in combination with a mechanism or device other than the centrifugal compressor 13 as long as it is capable of converting the working fluid energy into mechanical power (for example, rotational force). In addition, there is no need to limit the use of the turbine 12.

As shown in FIG. 1, a turbocharger 1 according to some embodiments is configured to be driven by the energy of exhaust gas discharged from an internal combustion engine 11 and to compress a fluid (e.g., air). The turbocharger 1 includes a turbine 12 and a centrifugal compressor 13 configured to be driven by the turbine 12.

2, the turbine 12 includes a variable nozzle device 2, a turbine wheel 3, and a housing 4 configured to accommodate the variable nozzle device 2 and the turbine wheel 3. In the illustrated embodiment, the housing 4 includes a first housing (turbine housing) 4A and a second housing (bearing housing) 4B configured to accommodate the variable nozzle device 2 and the turbine wheel 3 between the first housing 4A and the second housing 4B.

As shown in FIG. 1, the centrifugal compressor 13 includes a centrifugal impeller 14 and a compressor housing 15 configured to rotatably accommodate the impeller 14 between the second housing 4B.

1, the turbocharger 1 further includes a rotating shaft 16 having the turbine wheel 3 connected to one side and the impeller 14 connected to the other side, and a bearing 17 configured to rotatably support the rotating shaft 16 between the turbine wheel 3 and the impeller 14. The second housing 4B is disposed between the first housing 4A and the compressor housing 15, and is connected to each of the first housing 4A and the compressor housing 15 via fastening members (not shown), such as bolts and nuts. The second housing 4B may be configured to accommodate the bearing 17, as shown in FIG. 1.

The turbine 12 of the turbocharger 1 is configured to rotate the turbine wheel 3 using the energy of exhaust gas discharged from the internal combustion engine 11. The impeller 14 is coaxially connected to the turbine wheel 3 via a rotating shaft 16, and is therefore driven to rotate about the axis LA in conjunction with the rotation of the turbine wheel 3. The centrifugal compressor 13 of the turbocharger 1 is configured to draw air (combustion gas) into the compressor housing 15, compress the air, and send the compressed air to the internal combustion engine 11 by driving the impeller 14 to rotate about the axis LA.

The compressed air sent from the centrifugal compressor 13 to the internal combustion engine 11 is used as an oxidizer for combustion in the internal combustion engine 11. The exhaust gas generated by the combustion in the internal combustion engine 11 is sent from the internal combustion engine 11 to the turbine 12, which rotates the turbine wheel 3.

(Impeller)
The impeller 14 is configured to guide air introduced along the axial direction of the impeller 14 to the outside in the radial direction of the impeller 14. In the illustrated embodiment, the impeller 14 is an open-type impeller that does not include an annular member surrounding the outer periphery of the blades of the impeller 14.

(Compressor housing)
The compressor housing 15 is formed with a gas introduction passage 151 and a scroll passage 152. The gas introduction passage 151 is a passage for taking in air (combustion gas) from outside the compressor housing 15 and guiding the taken-in air to the impeller 14. The gas introduction passage 151 extends along the axial direction of the impeller 14 and is provided on one side of the impeller 14 in the axial direction. By driving the impeller 14 to rotate, air is taken in from outside the compressor housing 15 into the gas introduction passage 151, and the taken-in air flows through the gas introduction passage 151 toward the impeller 14 and is guided to the impeller 14.

The scroll passage 152 is provided radially outside the impeller 14 so as to surround the periphery of the impeller 14, and consists of a spiral passage extending along the circumferential direction of the impeller 14. Air that passes through the impeller 14 and is compressed by the impeller 14 is guided to the scroll passage 152. The compressed air that has passed through the scroll passage 152 is guided to the internal combustion engine 11.

Hereinafter, the direction in which the axis LA of the turbine wheel 3 extends is referred to as the axial direction of the turbine wheel 3, the direction perpendicular to the axis LA is referred to as the radial direction of the turbine wheel 3, and the circumferential direction around the axis LA is referred to as the circumferential direction of the turbine wheel 3. In this disclosure, the axial direction, radial direction, and circumferential direction of the turbine wheel 3 may be simply referred to as the axial direction, radial direction, and circumferential direction, respectively. In the axial direction of the turbine wheel 3, the side where the first housing 4A is located relative to the second housing 4B (the right side in FIG. 2) is defined as the front side, and the side where the second housing 4B is located relative to the first housing 4A (the side opposite to the front side, the left side in FIG. 2) is defined as the rear side. Note that in this disclosure, "along a certain direction" includes not only a certain direction, but also a direction inclined within a range of ±15° relative to a certain direction.

(Turbine wheel)
As shown in Fig. 2, the turbine wheel 3 includes a hub 31 having a substantially truncated cone shape and a plurality of turbine blades 32 provided on the outer circumferential surface of the hub 31. The plurality of turbine blades 32 are arranged at intervals from one another in the circumferential direction around the axis line LA. The hub 31 and the plurality of turbine blades 32 are provided so as to be rotatable integrally with the rotating shaft 16 about the axis line LA. The turbine wheel 3 is configured to guide exhaust gas introduced from the outside in the radial direction of the turbine wheel 3 to the front side of the turbine wheel 3 along the axial direction of the turbine wheel 3. In the illustrated embodiment, the turbine wheel 3 is an open-type impeller that does not include an annular member surrounding the outer periphery of the turbine blades 32.

(Scroll passage, exhaust gas discharge passage)
The first housing 4A is formed with a scroll passage 41 for guiding exhaust gas discharged from the internal combustion engine 11 to the turbine wheel 3, and an exhaust gas discharge passage 42 for discharging exhaust gas that has passed through the turbine wheel 3 to the outside of the first housing 4A (turbine 12). In other words, the first housing 4A has the scroll passage 41 and the exhaust gas discharge passage 42. The scroll passage 41 is provided on the outer side in the radial direction of the turbine wheel 3 so as to surround the periphery of the turbine wheel 3, and is composed of a spiral passage extending along the circumferential direction. The exhaust gas discharge passage 42 extends toward the front side along the axial direction.

By fastening the first housing 4A and the second housing 4B together, an internal space 43 is formed between the first housing 4A and the second housing 4B, connecting the scroll passage 41 and the exhaust gas discharge passage 42. The variable nozzle device 2 and the turbine wheel 3 are disposed in the internal space 43, which is formed radially inward from the scroll passage 41. The turbine wheel 3 is accommodated rotatably relative to the first housing 4A and the second housing 4B.

The exhaust gas discharged from the internal combustion engine 11 is guided to the turbine wheel 3 via the scroll passage 41, and drives the turbine wheel 3 to rotate. The exhaust gas that drives the turbine wheel 3 to rotate is discharged to the outside of the first housing 4A (turbine 12) via the exhaust gas discharge passage 42.

(Variable nozzle device)
2, the variable nozzle device 2 includes a nozzle mount 5, at least one nozzle support 6 configured to have one side supported by the nozzle mount 5 and the other side in contact with another member 100, and a biasing member 7 configured to bias the nozzle mount 5 toward the other member 100. The nozzle mount 5 and the at least one nozzle support 6 are supported in the axial direction between the other member 100 and the biasing member 7 by the biasing force of the biasing member 7. In the embodiment shown in FIG. 2, the variable nozzle device 2 further includes a nozzle plate 8, at least one variable nozzle vane 21 (plural in the illustrated example), an annular member (drive ring) 22, and at least one link member (lever plate) 23 (plural in the illustrated example).

Hereinafter, the direction in which the axis LB of the variable nozzle device 2 extends is referred to as the axial direction of the variable nozzle device 2, the direction perpendicular to the axis LB is referred to as the radial direction of the variable nozzle device 2, and the circumferential direction around the axis LB is referred to as the circumferential direction of the variable nozzle device 2. The extension direction of the axis LB is the direction along the extension direction of the axis LA.

(Nozzle mount)
As shown in Fig. 2, the nozzle mount 5 forms a gas flow passage 43A from the scroll flow passage 41 toward the turbine wheel 3 between it and another member 100 (nozzle plate 8 in Fig. 2). The gas flow passage 43A is provided between the scroll flow passage 41 and the turbine wheel 3 in the radial direction of the turbine wheel 3 so as to surround the periphery (the outer side in the radial direction) of the turbine wheel 3. The gas flow passage 43A is a part of the internal space 43, and is formed on the outer circumferential side of the accommodation space that accommodates the turbine wheel 3 in the internal space 43. The nozzle mount 5 is located rearward of the gas flow passage 43A, and the other member 100 is located forward of the gas flow passage 43A.

The nozzle mount 5 includes an annular plate portion 51 that extends circumferentially around the variable nozzle device 2. The annular plate portion 51 is disposed on the outer circumferential side of the turbine wheel 3. The annular plate portion 51 has an annular mount-side flow passage surface 52 that faces the gas flow passage 43A on one side in the thickness direction of the annular plate portion 51, i.e., the front side. The annular plate portion 51 has an annular mount-side back surface 53 on the other side in the thickness direction of the annular plate portion 51 (the opposite side to the mount-side flow passage surface 52), i.e., the rear side.

(Nozzle plate)
2, the nozzle plate 8 includes an annular plate extending along the circumferential direction of the variable nozzle device 2. The nozzle plate 8 is disposed opposite the annular plate portion 51 with a gap therebetween, and forms a gas flow path 43A between the nozzle plate 8 and the annular plate portion 51. The nozzle plate 8 has an annular plate-side flow path surface 81 facing the gas flow path 43A on one side in the thickness direction of the nozzle plate 8, i.e., the rear side. The nozzle plate 8 has an annular plate-side back surface 82 on the other side in the thickness direction of the nozzle plate 8 (the opposite side to the plate-side flow path surface 81), i.e., the front side.

The gas flow passage 43A is formed between the mount side flow passage surface 52 and the plate side flow passage surface 81. The exhaust gas introduced into the inside of the turbine 12 passes through the scroll flow passage 41, then through the gas flow passage 43A, and is then led to the turbine wheel 3, causing the turbine wheel 3 to rotate.

As shown in FIG. 2, the second housing 4B has an opposing surface 45 that faces the rear surface of the turbine wheel 3 with a gap therebetween, and a recess 46 that is recessed rearward of the opposing surface 45, outside the outer edge of the opposing surface 45 in the radial direction. The bottom surface 461 of the recess 46 faces the mount-side rear surface 53, sandwiching a rear space 43B between it and the mount-side rear surface 53. The rear space 43B is part of the internal space 43, and is formed on the opposite side of the nozzle mount 5 to the gas flow path 43A.

(Variable nozzle vane)
Each of the multiple variable nozzle vanes 21 is disposed in the gas flow passage 43A, and is supported by the annular plate portion 51 so as to be rotatable about its own rotation center RC. The multiple variable nozzle vanes 21 are disposed at intervals in the circumferential direction of the turbine wheel 3.

The annular member (drive ring) 22 is disposed in the rear space 43B, and is configured to rotate about the axis LB of the variable nozzle device 2 relative to the nozzle mount 5 by an external driving force. As shown in FIG. 2, the turbine 12 further includes a drive mechanism (actuator) 25 configured to transmit a driving force to the annular member 22 to rotate the annular member 22 about its axis LB, and a control device (controller) 26 configured to control the rotation of the annular member 22 about the axis LB. The drive mechanism 25 includes an electric motor that generates a driving force, an air cylinder that transmits the driving force, and the like.

(Link member)
Fig. 3 is a schematic diagram of the variable nozzle device 2 according to an embodiment of the present disclosure, viewed from one axial side (rear side). As shown in Fig. 3, the variable nozzle device 2 includes the same number of link members (lever plates) 23 as the variable nozzle vanes 21. Each of the multiple link members 23 is disposed in the rear space 43B, has one end 231 connected to the annular member 22, and has the other end 232 connected to the corresponding variable nozzle vane 21, and is configured to change the blade angle of the variable nozzle vane 21 connected to the other end 232 in conjunction with the rotation of the annular member 22.

In the embodiment shown in FIG. 3, one end 231 of each link member 23 includes a fitting portion 231A that fits into a fitting portion 221 formed in the annular member 22. The fitting portion 221 includes a groove portion 221A formed in the outer periphery of the annular member 22, and the fitting portion 231A is accommodated inside the groove portion 221A and is adapted to fit loosely into the groove portion 221A.

The annular plate portion 51 has a plurality of through holes 55 penetrating the mount side flow passage surface 52 and the mount side back surface 53. The plurality of through holes 55 are arranged at intervals in the circumferential direction of the variable nozzle device 2. The annular plate portion 51 has the same number of through holes 55 as the variable nozzle vanes 21 and link members 23. The other end 232 of each link member 23 is inserted through the through hole 55 that individually corresponds to the link member 23, and is connected to the variable nozzle vane 21 that individually corresponds to the link member 23.

When the annular member 22 is rotated to one side in the circumferential direction of the variable nozzle device 2, adjacent variable nozzle vanes 21 in the circumferential direction move (rotate) away from each other, and the flow path cross-sectional area of the gas flow path 43A between the variable nozzle vanes 21 increases. When the annular member 22 is rotated to the other side in the circumferential direction of the variable nozzle device 2, adjacent variable nozzle vanes 21 in the circumferential direction move (rotate) toward each other, and the flow path cross-sectional area of the gas flow path 43A between the variable nozzle vanes 21 decreases.

The variable nozzle device 2 transmits the driving force from the drive mechanism 25 to the multiple variable nozzle vanes 21 via the annular member 22 and multiple link members 23, causing the multiple variable nozzle vanes 21 to rotate around their respective rotation centers RC, changing the blade angle of each, thereby adjusting the flow path cross-sectional area of the gas flow path 43A. The turbine 12 can change the flow velocity and pressure of the exhaust gas guided to the turbine wheel 3 by increasing or decreasing the flow path cross-sectional area of the gas flow path 43A using the variable nozzle device 2, thereby controlling the boost pressure of the turbine 12.

(Using member)
2, the biasing member 7 is an annular elastic member (disc spring) disposed in a compressed state in the axial direction between the opposing surface 45 of the second housing 4B and the mount-side back surface 53 of the nozzle mount 5. The biasing member 7 biases the mount-side back surface 53 toward the other member 100 (forward) by the opposing surface 45 receiving a reaction force of the biasing member 7. The nozzle mount 5 and the nozzle support 6 are supported between the biasing member 7 and the other member 100 in the axial direction by the biasing force of the biasing member 7.

The nozzle mount 5 and the nozzle support 6 are not restricted in their movement along the axial direction between the biasing member 7 and the other member 100 in the axial direction. In the embodiment shown in FIG. 2, the first housing 4A has a rear scroll flow passage surface 441 facing the rear side of the scroll flow passage 41, and has an inward protrusion 44 extending radially inward along the radial direction. The nozzle mount 5 is not in contact with the inward protrusion 44, with the outer peripheral end of the annular plate portion 51 facing the inner peripheral end of the inward protrusion 44 with a gap between them.

In the embodiment shown in FIG. 2, the variable nozzle device 2 further includes a positioning pin 56 that limits the movement of the nozzle mount 5 in the radial direction. One end of the positioning pin 56 is inserted into a first hole formed in the mount-side rear surface 53 of the nozzle mount 5, and the other end is inserted into a second hole formed in the surface of the second housing 4B that faces the mount-side rear surface 53. The positioning pin 56 is loosely inserted into at least one of the first hole or the second hole, and does not limit the movement of the nozzle mount 5 in the axial direction caused by the biasing force of the biasing member 7, but does limit the movement of the nozzle mount 5 in the radial direction.

In the embodiment shown in FIG. 2, each of the multiple turbine blades 32 is arranged with a predetermined gap from the shroud surface 47, which is the inner surface of the first housing 4A. The first housing 4A has an annular recess 48 formed therein, the recess 48 being composed of an outer peripheral surface 481 extending forward from the outer peripheral end of the shroud surface 47 along the axial direction, and an annular bottom surface 482 extending outward from the forward end of the outer peripheral surface 481 along the radial direction. The nozzle plate 8 is inserted into the recess 48.

In the embodiment shown in FIG. 2, the first housing 4A has an annular protruding portion 483 that protrudes radially outward from the bottom surface 482 and toward the rear side from the bottom surface 482. The protruding portion 483 has an annular housing-side abutment surface 484 facing the gas flow path 43A on the rear side. The nozzle plate 8 is configured such that the inner peripheral end of the nozzle plate 8 faces the outer peripheral surface 481 with a gap therebetween, and the plate-side back surface 82 abuts against the housing-side abutment surface 484. The nozzle plate 8 is supported between the nozzle support 6 and the first housing 4A in the axial direction by being biased toward the first housing 4A in the axial direction by the biasing force of the biasing member 7 via the nozzle support 6.

(Nozzle support)
Fig. 4 is a schematic cross-sectional view taken along the axis LB of the variable nozzle device 2 according to an embodiment of the present disclosure. The nozzle support 6 supports two members (the nozzle mount 5 and the nozzle plate 8 in Fig. 2) that form the above-mentioned gas flow passage 43A in a state spaced apart from each other. In the illustrated embodiment, the variable nozzle device 2 includes a plurality of nozzle supports 6 that are spaced apart from each other in the circumferential direction of the variable nozzle device 2 as shown in Fig. 2. Each of the plurality of nozzle supports 6 is disposed radially outward of the plurality of variable nozzle vanes 21.

As shown in FIG. 4, each of the nozzle supports 6 is a rod-shaped member extending along the central axis LD of the nozzle support 6. As shown in FIG. 2, the nozzle support 6 has a fixing portion 61 fixed to the nozzle mount 5 on one axial side of the nozzle support 6, and a main body portion 62 arranged in the gas flow path 43A on the other axial side of the nozzle support 6. In the illustrated embodiment, the fixing portion 61 is fixed to the nozzle mount 5 by being swaged into a hole 54 formed in the mount-side flow path surface 52 of the nozzle mount 5. The fixing portion 61 may be fixed to the nozzle mount 5 by a fixing method other than swaging, such as by being pressed into the nozzle mount 5.

The biasing member 7 described above biases each of the nozzle supports 6 toward the other member 100 via the nozzle mount 5. The main body 62 of each of the nozzle supports 6 has an abutment surface 63 that abuts against the other member 100 that forms a gas flow path 43A between the nozzle mount 5 (see FIG. 4). The abutment surface 63 is an end face opposite to the side integrally connected to the fixed portion 61 of the main body 62. In the embodiment shown in FIG. 4, each of the nozzle supports 6 has a central axis LD that extends in a direction parallel to the axis LB. Each of the nozzle supports 6 has an abutment surface 63 that abuts against the plate-side flow path surface 81.

In some embodiments, as shown in FIG. 4, each of the multiple nozzle supports 6 includes the above-mentioned abutment surface 63 that abuts against the other member 100, and a curved surface 64 whose inner edge is connected to the outer edge of the abutment surface 63. The curved surface 64 has a contour shape that is convexly curved in a direction away from the central axis LD of the nozzle support 6 on which the curved surface 64 is formed. In the embodiment shown in FIG. 4, the curved surface 64 is formed on the main body portion 62, and the outer edge of the curved surface 64 is connected to the outer surface (outer peripheral surface) 621 of the main body portion 62.

FIG. 5 is an explanatory diagram for explaining thermal deformation of a variable nozzle device 02 according to a comparative example. FIG. 6 is an explanatory diagram for explaining thermal deformation of a variable nozzle device 2 according to an embodiment of the present disclosure. The nozzle support 06 provided in the variable nozzle device 02 has a fixing part 061 fixed to the nozzle mount 5 and a main body part 062 arranged in the gas flow path 43A. The main body part 062 has an abutment surface 063 that abuts against another member 100. The outer edge 0631 of the abutment surface 063 is connected to the outer surface (outer peripheral surface) of the main body part 062. The outer edge 0631 may be subjected to R processing to the extent that is normally performed.

As shown in Figures 5 and 6, exhaust gas flowing through gas flow path 43A causes thermal deformation in the two components (nozzle mount 5 and other component 100) that form gas flow path 43A, and due to the difference in thermal deformation of the two components, nozzle support 6 may come into contact with other component 100 with its central axis LD tilted relative to a direction parallel to axis LB. In the embodiment shown in Figures 5 and 6, nozzle mount 5 and other component 100 are thermally deformed in directions that move them away from each other in the axial direction, and nozzle support 6 is tilted so that the other component 100 side of nozzle support 6 is farther away from axis LB than the nozzle mount 5 side.

In the variable nozzle device 02 according to the comparative example, as shown in Figure 5, when the outer edge 0631 of the abutment surface 063 comes into contact with another member 100 due to the above-mentioned thermal deformation, localized stress concentration occurs at the outer edge 0631 of the abutment surface 063, and there is a risk that the nozzle support 6 may be broken or damaged. In contrast, in the variable nozzle device 2 of the present disclosure, as shown in Figure 6, when the curved surface 64 comes into contact with another member 100 due to the above-mentioned thermal deformation, the contour shape of the curved surface 64 can alleviate stress concentration at the curved surface 64.

According to the above configuration, by providing the nozzle support 6 with a curved surface 64, stress concentration can be alleviated when the curved surface 64 of the nozzle support 6 comes into contact with the other member 100 due to the difference in thermal deformation that occurs between the nozzle mount 5 and the other member 100. By alleviating the stress concentration of the nozzle support 6, breakage or damage caused by stress concentration of the nozzle support 6 can be suppressed.

As shown in FIG. 2, the variable nozzle device 2 according to some embodiments includes a nozzle plate 8 having a plate-side flow path surface 81 that forms a gas flow path 43A between the nozzle mount 5 and the nozzle plate 8, and against which the abutment surface 63 of at least one nozzle support 6 described above abuts. The other member 100 described above is made of the nozzle plate 8.

The above configuration reduces stress concentration when the curved surface 64 of the nozzle support 6 abuts against the plate-side flow path surface 81 due to the difference in thermal deformation that occurs between the nozzle mount 5 and the nozzle plate 8.

This disclosure is also applicable to a variable nozzle device 2 that does not include the nozzle plate 8 described above. FIG. 7 is a schematic cross-sectional view along the axis LA of the turbine 12 according to one embodiment of the present disclosure. In the variable nozzle device 2 according to some embodiments, as shown in FIG. 7, the other member 100 described above is made of a housing 4 (first housing 4A). The first housing 4A has a housing side flow path surface 491 that forms a gas flow path 43A between itself and the nozzle mount 5, and has a housing side flow path surface 491 against which the abutment surface 63 of at least one nozzle support 6 described above abuts.

In the embodiment shown in FIG. 7, the first housing 4A includes a flow passage surface forming portion 49 having a housing side flow passage surface 491. The housing side flow passage surface 491 is an annular surface extending along the circumferential direction and extends along the radial direction. The inner peripheral end of the housing side flow passage surface 491 is connected to the outer peripheral end of the shroud surface 47 and is continuous with the shroud surface 47.

In the variable nozzle device 2 according to some embodiments, as shown in FIG. 4, at least one of the nozzle supports 6 described above satisfies the condition 0.1D1≦R1, where D1 is the maximum diameter of the outer surface 621 of the nozzle support 6 and R1 is the radius of curvature of the curved surface 64. The curved surface 64 that satisfies the condition 0.1D1≦R1 has a contour shape that is gentler than a machined surface formed by normal R machining, and therefore can effectively alleviate stress concentration when the curved surface 64 of the nozzle support 6 abuts against another member 100.

In the variable nozzle device 2 according to some embodiments, as shown in FIG. 4, at least one nozzle support 6 includes a constricted portion 65 formed on the outer surface 621 of the nozzle support 6. The constricted portion 65 includes a concave curved surface portion 651 that is recessed inward in the radial direction from one side (the nozzle mount 5 side) toward the other side (the other member 100 side) in the axial direction, and a convex curved surface portion 652 that bulges outward in the radial direction from the one side (the nozzle mount 5 side) toward the other side (the other member 100 side).

In some embodiments, as shown in FIG. 4, at least one nozzle support 6 described above satisfies the conditions R1<R2 and R1<R3 when the radius of curvature of the curved surface 64 is R1, the radius of curvature of the concave curved surface portion 651 is R2, and the radius of curvature of the convex curved surface portion 652 is R3. In this case, by making the contour shapes of the concave curved surface portion 651 and the convex curved surface portion 652 gentler than the contour shape of the curved surface 64, it is possible to suppress stress concentration in the constriction portion 65. Note that the present disclosure is also applicable to cases where the conditions R1<R2 and R1<R3 are not satisfied.

In some embodiments, as shown in FIG. 4, at least one of the nozzle supports 6 satisfies the condition D2≦D3 when the diameter (maximum diameter) of the contact surface 63 is D2 and the minimum diameter of the constricted portion 65 is D3. In this case, the contact surface 63 that satisfies the condition D2≦D3 has a relatively small diameter D2, so the contour shape of the curved surface 64 can be made gentler than when the diameter D2 is large, and this effectively reduces stress concentration when the curved surface 64 of the nozzle support 6 abuts against another member 100. Note that the present disclosure is also applicable to cases where the condition D2≦D3 is not satisfied.

As shown in Figures 2 and 7, the turbine 12 according to some embodiments includes the variable nozzle device 2 described above, a turbine wheel 3, and a housing 4 that accommodates the turbine wheel 3 and the variable nozzle device 2. As shown in Figure 1, the turbocharger 1 according to some embodiments includes the turbine 12 described above and the centrifugal compressor 13 described above. In this case, the variable nozzle device 2 described above suppresses damage to the nozzle support 6, thereby improving the reliability of the turbine 12 and turbocharger 1 that include the variable nozzle device 2.

In this specification, expressions expressing relative or absolute configuration, such as "in a certain direction,""along a certain direction,""parallel,""orthogonal,""center,""concentric," or "coaxial," do not only strictly represent such a configuration, but also represent 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 indicating that things are in an equal state, such as "identical,""equal," and "homogeneous," 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 describing shapes such as a rectangular shape or a cylindrical shape do not only refer to shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained.
In addition, in this specification, the expressions "comprise,""include," or "have" a certain element are not exclusive expressions that exclude the presence of other elements.

This disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these embodiments.

The contents described in the above-mentioned embodiments can be understood, for example, as follows:

1) A variable nozzle device (2) according to at least one embodiment of the present disclosure,
A variable nozzle device (2) housed together with a turbine wheel (3) in a housing (4),
A nozzle mount (5);
At least one nozzle support (6) configured such that one side is supported by the nozzle mount (5) and the other side is in contact with another member (100);
and a biasing member (7) configured to bias the nozzle mount (5) toward the other member (100),
the nozzle mount (5) and the at least one nozzle support (6) are supported between the other member (100) and the biasing member (7) in the axial direction by the biasing force of the biasing member (7);
The at least one nozzle support (6)
An abutment surface (63) that abuts against the other member (100);
and a curved surface (64) whose inner edge is connected to the outer edge of the abutment surface (63), the curved surface (64) having a contour shape that is convexly curved in a direction away from the central axis (LD) of the nozzle support (6).

According to the configuration of 1) above, by providing the nozzle support (6) with a curved surface (64), stress concentration can be alleviated when the curved surface (64) of the nozzle support (6) abuts against the other member (100) due to the difference in thermal deformation that occurs between the nozzle mount (5) and the other member (100). By alleviating the stress concentration on the nozzle support (6), damage to the nozzle support (6) can be suppressed.

2) In some embodiments, the variable nozzle device (2) described in 1) above,
a nozzle plate (8) having a plate-side flow path surface (81) that forms a gas flow path (43A) toward the turbine wheel (12) between the nozzle mount (5) and the plate-side flow path surface (81) with which the abutment surface (63) of the at least one nozzle support (6) abuts;
The other member (100) is composed of the nozzle plate (8).

The configuration of 2) above allows stress concentration to be alleviated when the curved surface (64) of the nozzle support (6) abuts against the plate-side flow path surface (81) due to the difference in thermal deformation that occurs between the nozzle mount (5) and the nozzle plate (8).

3) In some embodiments, the variable nozzle device (2) described in 1) above,
The other member (100) is composed of the housing (4) having a housing side flow path surface (491) that forms a gas flow path (43A) toward the turbine wheel (12) between the nozzle mount (5) and the housing (4), and the housing side flow path surface (491) with which the abutment surface (63) of the at least one nozzle support (6) abuts.

The configuration of 3) above reduces stress concentration when the curved surface (64) of the nozzle support (6) abuts against the housing side flow path surface (491) due to the difference in thermal deformation that occurs between the nozzle mount (5) and the housing (4).

4) In some embodiments, the variable nozzle device (2) according to any one of 1) to 3) above,
The at least one nozzle support (6) satisfies the condition 0.1D1≦R1, where D1 is the maximum diameter of the outer surface (621) of the nozzle support (6) and R1 is the radius of curvature of the curved surface (64).

According to the configuration of 4) above, the curved surface (64) that satisfies the condition 0.1D1≦R1 has a contour shape that is gentler than the processed surface formed by normal R processing, so that it is possible to effectively reduce stress concentration when the curved surface (64) of the nozzle support (6) abuts against another member (100).

5) In some embodiments, the variable nozzle device (2) according to any one of 1) to 4) above,
The at least one nozzle support (6)
a constriction portion (65) formed on an outer surface (621) of the nozzle support (6), the constriction portion (65) including a concave curved surface portion (651) that is recessed radially inward as it moves from the one side to the other side, and a convex curved surface portion (652) that bulges radially outward as it moves from the one side to the other side,
When the radius of curvature of the curved surface (64) is R1, the radius of curvature of the concave curved surface portion (651) is R2, and the radius of curvature of the convex curved surface portion (652) is R3, the conditions R1<R2 and R1<R3 are satisfied.

In the configuration of 5) above, the contour shapes of the concave curved surface portion (651) and the convex curved surface portion (652) are made gentler than the contour shape of the curved surface (64), thereby preventing stress concentration in the constricted portion (65).

6) In some embodiments, the variable nozzle device (2) according to any one of 1) to 5) above,
The at least one nozzle support (6)
a constriction portion (65) formed on an outer surface (621) of the nozzle support (6), the constriction portion (65) including a concave curved surface portion (651) that is recessed radially inward as it moves from the one side to the other side, and a convex curved surface portion (652) that bulges radially outward as it moves from the one side to the other side,
When the diameter of the contact surface (63) is D2 and the minimum diameter of the constricted portion (65) is D3, the condition D2≦D3 is satisfied.

According to the configuration of 6) above, the contact surface (63) that satisfies the condition D2≦D3 has a relatively small diameter D2, and therefore the contour shape of the curved surface (64) can be made gentler than when the diameter D2 is large, and this effectively reduces stress concentration when the curved surface (64) of the nozzle support (6) contacts another member (100).

7) A turbine (12) according to at least one embodiment of the present disclosure,
A variable nozzle device (2) according to any one of 1) to 6) above;
The turbine wheel (3);
and the housing (4) that houses the turbine wheel (3) and the variable nozzle device (2).

The configuration of 7) above can improve the reliability of the turbine (12) by suppressing damage to the nozzle support (6) of the variable nozzle device (2).

8) A turbocharger (1) according to at least one embodiment of the present disclosure,
A turbine (12) according to 7) above;
and a centrifugal compressor (13) configured to be driven by the turbine (12).

The configuration of 8) above can improve the reliability of the turbocharger (1) by suppressing damage to the nozzle support (6) of the variable nozzle device (2).

1 turbocharger 2 variable nozzle device 3 turbine wheel 4 housing 4A first housing 4B second housing 5 nozzle mount 6 nozzle support 7 biasing member 8 nozzle plate 10 internal combustion engine system 11 internal combustion engine 12 turbine 13 centrifugal compressor 14 impeller 15 compressor housing 16 rotating shaft 17 bearing 21 variable nozzle vane 22 annular member 23 link member 25 drive mechanism 31 hub 32 turbine blade 41 scroll passage 42 exhaust gas discharge passage 43 internal space 43A gas passage 43B rear space 44 inward protrusion 45 opposing surface 46, 48 recess 47 shroud surface 51 annular plate portion 52 mount side passage surface 53 mount side back surface 56

positioning pin

61, 061 fixing

portion

62, 062

main body portion

63, 063 abutment surface 64 curved surface 65 constricted portion 81 Plate side flow passage surface 82 Plate side back surface 100 Other members

Claims

A variable nozzle device accommodated together with a turbine wheel in a housing,
A nozzle mount,
At least one nozzle support, one side of which is supported by the nozzle mount and the other side of which is configured to abut against another member;
a biasing member configured to bias the nozzle mount toward the other member,
the nozzle mount and the at least one nozzle support are supported between the other member and the biasing member in the axial direction by a biasing force of the biasing member,
The at least one nozzle support comprises:
a contact surface that contacts the other member;
a curved surface having an inner edge connected to an outer edge of the abutment surface, the curved surface having a contour shape that is convexly curved in a direction away from the central axis of the nozzle support,
Variable nozzle device.
a nozzle plate having a plate-side flow path surface that forms a gas flow path toward the turbine wheel between the nozzle mount and the nozzle plate, the plate-side flow path surface being in contact with the abutment surface of the at least one nozzle support;
The other member is the nozzle plate.
The variable nozzle device according to claim 1 .
the other member is a housing having a housing-side flow path surface that forms a gas flow path toward the turbine wheel between the nozzle mount and the housing, the housing having a housing-side flow path surface with which the abutment surface of the at least one nozzle support abuts;
The variable nozzle device according to claim 1 .
the at least one nozzle support satisfies the condition 0.1D1≦R1, where D1 is a maximum diameter of an outer surface of the nozzle support and R1 is a radius of curvature of the curved surface;
The variable nozzle device according to any one of claims 1 to 3.
The at least one nozzle support comprises:
a constricted portion formed on an outer surface of the nozzle support, the constricted portion including a concave curved surface portion that is concave inward in the radial direction as it moves from the one side to the other side, and a convex curved surface portion that bulges outward in the radial direction as it moves from the one side to the other side,
When the radius of curvature of the curved surface is R1, the radius of curvature of the concave curved surface portion is R2, and the radius of curvature of the convex curved surface portion is R3, the conditions R1<R2 and R1<R3 are satisfied.
The variable nozzle device according to any one of claims 1 to 3.
The at least one nozzle support comprises:
a constricted portion formed on an outer surface of the nozzle support, the constricted portion including a concave curved surface portion that is concave inward in the radial direction as it moves from the one side to the other side, and a convex curved surface portion that bulges outward in the radial direction as it moves from the one side to the other side,
When the diameter of the contact surface is D2 and the minimum diameter of the constricted portion is D3, the condition D2≦D3 is satisfied.
The variable nozzle device according to any one of claims 1 to 3.
A variable nozzle device according to any one of claims 1 to 3;
The turbine wheel;
the housing containing the turbine wheel and the variable nozzle device.
A turbine according to claim 7;
a centrifugal compressor configured to be driven by the turbine.