CN120712399A

CN120712399A - Variable nozzle device, turbine, and turbocharger

Info

Publication number: CN120712399A
Application number: CN202380095077.9A
Authority: CN
Inventors: 内海航介; 加藤永护
Original assignee: Mitsubishi Heavy Industries Engine and Turbocharger Ltd
Current assignee: Mitsubishi Heavy Industries Engine and Turbocharger Ltd
Priority date: 2023-03-30
Filing date: 2023-03-30
Publication date: 2025-09-26
Also published as: WO2024201959A1

Abstract

A variable nozzle device housed in a casing together with a turbine impeller comprises: a nozzle mounting seat; at least one nozzle bracket, which is configured to be supported on the nozzle mounting seat on one side and abut against other components on the other side; and a force-applying component, which is configured to apply force to the nozzle mounting seat toward the other component side, and the nozzle mounting seat and at least one nozzle bracket are axially supported between the other component and the force-applying component by the force of the force-applying component, and at least one nozzle bracket includes: an abutting surface, which abuts against other components; and a curved surface, the inner edge of which is connected to the outer edge of the abutting surface, and has a contour shape that is convexly curved in a direction away from the central axis of the nozzle bracket.

Description

Variable nozzle device, turbine, and turbocharger

Technical Field

The present invention relates to a variable nozzle device, and a turbine and a turbocharger provided with the variable nozzle device.

Background

As a turbocharger (supercharger) that supercharges intake air of an internal combustion engine (engine) using energy of exhaust gas of the internal combustion engine, a turbocharger provided with a variable-capacity turbine is known (for example, refer to patent document 1). The variable capacity turbine has a plurality of nozzle blades arranged in the circumferential direction of the turbine wheel in an exhaust gas flow path for conveying exhaust gas from a scroll flow path of the turbine to the turbine wheel, and the vane angle of the nozzle blades is changed from the outside by an actuator, so that the flow path cross-sectional area of the exhaust gas flow path (flow path between adjacent nozzle blades) can be adjusted. The variable capacity turbine improves the supercharging effect by adjusting the flow path cross-sectional area of the exhaust gas flow path and changing the flow velocity or pressure of the exhaust gas guided by the turbine wheel.

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

Technical literature of the prior art

Patent literature

Patent document 1 specification of U.S. Pat. No. 8684678

Disclosure of Invention

Technical problem to be solved by the invention

In the invention described in patent document 1, the two annular plate members are thermally deformed by the high-temperature exhaust gas flowing through the exhaust gas flow path, and relatively high stress is generated between the nozzle holder and the annular plate member in contact with the nozzle holder due to the difference in thermal deformation of the two annular plate members, so that the nozzle holder is broken or damaged.

In view of the above, an object of at least one embodiment of the present invention is to provide a variable nozzle device, a turbine and a turbocharger including the variable nozzle device, which can reduce stress generated between a nozzle holder and other members that are in contact with the nozzle holder.

Means for solving the technical problems

A variable nozzle device according to at least one embodiment of the present invention is a variable nozzle device housed in a casing together with a turbine wheel, the variable nozzle device including:

A nozzle mount;

at least one nozzle support, one side of which is supported by the nozzle mounting seat and the other side of which is in contact with other components, and

A biasing member configured to bias the nozzle mount toward the other member,

The nozzle mount and the at least one nozzle holder are supported between the other member and the biasing member in the axial direction by the biasing force of the biasing member,

The at least one nozzle support includes:

An abutment surface abutting the other member, and

And a curved surface having an inner edge connected to an outer edge of the contact surface and having a contour shape curved in a convex shape in a direction away from a central axis of the nozzle holder.

The turbine according to at least one embodiment of the present invention includes:

the variable nozzle device;

The turbine wheel

The housing accommodates the turbine wheel and the variable nozzle device.

A turbocharger according to at least one embodiment of the present invention includes:

the turbine is provided with

And a centrifugal compressor configured to be driven by the turbine.

Effects of the invention

According to at least one embodiment of the present invention, there are provided a variable nozzle device, a turbine and a turbocharger including the variable nozzle device, which can reduce stress generated between a nozzle holder and another member that is in contact with the nozzle holder.

Drawings

Fig. 1 is a schematic view of an internal combustion engine system including a turbocharger and an internal combustion engine according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view taken along the axis of a turbine according to an embodiment of the present invention.

Fig. 3 is a schematic view of a variable nozzle device according to an embodiment of the present invention, viewed from one side in the axial direction.

Fig. 4 is a schematic cross-sectional view taken along the axis of a variable nozzle device according to an embodiment of the present invention.

Fig. 5 is an explanatory view for explaining thermal deformation of the variable nozzle device according to the comparative example.

Fig. 6 is an explanatory view for explaining thermal deformation of the variable nozzle device according to the embodiment of the present invention.

Fig. 7 is a schematic cross-sectional view taken along the axis of a turbine according to an embodiment of the present invention.

Detailed Description

Several embodiments of the present invention will be described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the constituent components described as the embodiments or shown in the drawings are not intended to limit the scope of the present invention to these, but 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 invention. Fig. 2 is a schematic cross-sectional view taken along an axis LA of the turbine 12 according to an embodiment of the present invention. The turbine 12 according to the present invention may be mounted on, for example, a turbocharger (supercharger) 1 for an automobile, a ship, or an industrial use (for example, for land power generation). In the following embodiment, the turbine 12 mounted on the turbocharger 1 is described as an example, but the turbine 12 according to the present invention is not limited to the turbine mounted on the turbocharger 1. Also, the working fluid of the turbine 12 need not be limited to exhaust gas. That is, the turbine 12 of the present invention may be configured by itself or in combination with a mechanism or device other than the centrifugal compressor 13 as long as it can convert the working fluid energy into mechanical power (for example, rotational force). Further, the use of the turbine 12 and the like are not limited.

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

As shown in fig. 2, the turbine 12 includes a variable nozzle device 2, a turbine wheel 3, and a casing 4 configured to house the variable nozzle device 2 and the turbine wheel 3. In the illustrated embodiment, the casing 4 includes a1 st casing (turbine casing) 4A and a 2 nd casing (bearing casing) 4B configured to accommodate the variable nozzle device 2 and the turbine wheel 3 between the 1 st casing 4A and the turbine casing 4A.

As shown in fig. 1, the centrifugal compressor 13 includes a centrifugal impeller 14 and a compressor housing 15 configured to rotatably house the impeller 14 with the 2 nd housing 4B.

As shown in fig. 1, the turbocharger 1 further includes a rotary 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 rotary shaft 16 between the turbine wheel 3 and the impeller 14. The 2 nd casing 4B is disposed between the 1 st casing 4A and the compressor casing 15, and is coupled to the 1 st casing 4A and the compressor casing 15 via fastening members (not shown) such as bolts or nuts, respectively. As shown in fig. 1, the 2 nd housing 4B may be configured to accommodate the bearing 17.

The turbine 12 of the turbocharger 1 is configured to rotate the turbine wheel 3 by energy of exhaust gas discharged from the internal combustion engine 11. The impeller 14 is coaxially coupled to the turbine impeller 3 via the rotation shaft 16, and is thus rotationally driven about the axis LA in association with the rotation of the turbine impeller 3. The centrifugal compressor 13 of the turbocharger 1 is configured to suck air (combustion gas) into the compressor housing 15 by rotationally driving the impeller 14 about the axis LA, compress the air, and deliver the compressed air to the internal combustion engine 11.

Compressed air delivered from the centrifugal compressor 13 to the internal combustion engine 11 is supplied as an oxidant to 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, and 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 constituted by an open impeller that does not include an annular member surrounding the outer periphery of the blades of the impeller 14.

(Compressor housing)

A gas introduction flow path 151 and a scroll flow path 152 are formed in the compressor housing 15. The gas introduction flow path 151 is a flow path for sucking air (combustion gas) from outside the compressor housing 15 and guiding the sucked air to the impeller 14. The gas introduction flow path 151 extends along the axial direction of the impeller 14 and is provided at a position on the axial side of the impeller 14. By rotationally driving the impeller 14, air is sucked into the gas introduction flow passage 151 from the outside of the compressor housing 15, and the sucked air flows through the gas introduction flow passage 151 toward the impeller 14 to be guided to the impeller 14.

The scroll flow path 152 is constituted by a scroll-like flow path that is provided radially outside the impeller 14 so as to surround the periphery of the impeller 14 and extends in the circumferential direction of the impeller 14. The air passing through the impeller 14 and compressed by the impeller 14 is directed to the scroll flow path 152. The compressed air passing through the scroll flow path 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 orthogonal 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 the present invention, the axial direction, the radial direction, and the circumferential direction of the turbine wheel 3 are sometimes simply referred to as the axial direction, the radial direction, and the circumferential direction, respectively. In the axial direction of the turbine wheel 3, the side of the 1 st casing 4A relative to the 2 nd casing 4B (right side in fig. 2) is defined as a front side, and the side of the 2 nd casing 4B relative to the 1 st casing 4A (opposite to the front side) is defined as a rear side. In addition, the term "along a certain direction" in the present invention includes not only a certain direction but also a direction inclined within ±15° with respect to the certain direction.

(Turbine impeller)

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 an outer peripheral surface of the hub 31. The plurality of turbine blades 32 are arranged at intervals in the circumferential direction around the axis LA. The hub 31 and the plurality of turbine blades 32 are provided so as to be rotatable integrally with the rotary shaft 16 about an axis LA. The turbine wheel 3 is configured to guide the exhaust gas introduced from the radially outer side 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 constituted by an open-type impeller that does not include an annular member around the outer circumference of the turbine blades 32.

(Vortex flow passage, exhaust gas discharge flow passage)

A scroll flow path 41 for guiding exhaust gas discharged from the internal combustion engine 11 to the turbine wheel 3 and an exhaust gas discharge flow path 42 for discharging exhaust gas passing through the turbine wheel 3 to the outside of the 1 st housing 4A (turbine 12) are formed in the 1 st housing 4A. In other words, the 1 st housing 4A has the scroll flow path 41 and the exhaust gas discharge flow path 42. The scroll flow path 41 is constituted by a scroll-like flow path that is provided radially outside the turbine wheel 3 so as to surround the periphery of the turbine wheel 3 and extends in the circumferential direction. The exhaust gas discharge passage 42 extends toward the front side along the axial direction.

By fastening the 1 st housing 4A and the 2 nd housing 4B, an internal space 43 connecting the scroll flow path 41 and the exhaust gas discharge flow path 42 is formed between the 1 st housing 4A and the 2 nd housing 4B. The variable nozzle device 2 and the turbine wheel 3 are disposed in an inner space 43 formed on the radial direction inside the scroll flow path 41. The turbine wheel 3 is housed rotatably in the 1 st casing 4A and the 2 nd casing 4B.

The exhaust gas discharged from the internal combustion engine 11 is guided to the turbine wheel 3 via the scroll flow path 41, and the turbine wheel 3 is driven to rotate. The exhaust gas that rotationally drives the turbine wheel 3 is discharged to the outside of the 1 st casing 4A (turbine 12) via the exhaust gas discharge flow path 42.

(Variable nozzle device)

As shown in fig. 2, the variable nozzle device 2 includes a nozzle mount 5, at least one nozzle holder 6 having one side supported by the nozzle mount 5 and the other side abutting against the other member 100, and a biasing member 7 configured to bias the nozzle mount 5 toward the other member 100. The nozzle mount 5 and at least one nozzle holder 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 (a plurality of in the example shown in the drawing) variable nozzle vane 21, an annular member (a drive ring) 22, and at least one (a plurality of in the example shown in the drawing) link member (lever plate) 23.

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 orthogonal 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 extending direction of the axis LB is a direction along the extending direction of the axis LA.

(Nozzle mount)

As shown in fig. 2, the nozzle mount 5 forms a gas flow path 43A from the scroll flow path 41 toward the turbine wheel 3 between the other members 100 (the nozzle plate 8 in fig. 2). The gas flow path 43A is provided between the scroll flow path 41 and the turbine wheel 3 in the radial direction of the turbine wheel 3 so as to surround the periphery (radially outside) of the turbine wheel 3. The gas flow path 43A is a part of the inner space 43, and is formed in the inner space 43 at a position on the outer peripheral side than the accommodation space accommodating the turbine wheel 3. The nozzle mount 5 is located at the rear side of the gas flow path 43A, and the other member 100 is located at the front side of the gas flow path 43A.

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

(Nozzle plate)

As shown in fig. 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 to the annular plate 51 with a gap therebetween, and forms a gas flow path 43A with the annular plate 51. The nozzle plate 8 has an annular plate-side flow path 81 facing the gas flow path 43A on one side in the thickness direction of the nozzle plate 8, that is, on the rear side. The nozzle plate 8 has an annular plate-side back surface 82 on the other side (the side opposite to the plate-side flow surface 81) in the thickness direction of the nozzle plate 8, that is, on the front side.

The gas flow path 43A is formed between the mount-side flow path 52 and the plate-side flow path 81. The exhaust gas introduced into the turbine 12 passes through the scroll flow path 41, then passes through the gas flow path 43A, and is then introduced into the turbine wheel 3, thereby rotating the turbine wheel 3.

As shown in fig. 2, the 2 nd casing 4B has an opposing surface 45 opposing the back surface of the turbine wheel 3 with a gap therebetween, and a recess 46 recessed rearward of the opposing surface 45 on the outer side in the radial direction than the outer edge of the opposing surface 45. The bottom surface 461 of the recess 46 faces the mount-side rear surface 53 with the rear space 43B therebetween. The rear space 43B is a part of the internal space 43, and is formed on the opposite side of the gas flow path 43A with the nozzle mount 5 interposed therebetween.

(Variable nozzle vane)

The plurality of variable nozzle vanes 21 are each disposed in the gas flow path 43A and are rotatably supported around the rotation center RC of each annular plate 51. The plurality of variable nozzle vanes 21 are arranged 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 with respect 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 the axis LB thereof, and a control device (controller) 26 configured to control rotation of the annular member 22 about the axis LB. The driving mechanism 25 includes an electric motor that generates driving force, a cylinder that transmits driving force, and the like.

(Connecting rod part)

Fig. 3 is a schematic view of the variable nozzle device 2 according to the embodiment of the present invention, as seen from one side (rear side) in the axial direction. 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. The plurality of link members 23 are disposed in the rear space 43B, respectively, and have one end 231 connected to the annular member 22 and the other end 232 connected to the corresponding variable nozzle vane 21, and are configured to change the vane angle of the variable nozzle vane 21 connected to the other end 232 in association with the rotation of the annular member 22.

In the embodiment shown in fig. 3, one end 231 of each link member 23 includes an engagement portion 231A that engages with the engaged portion 221 formed in the annular member 22. The fitted portion 221 includes a groove 221A formed in the outer peripheral edge portion of the annular member 22, and the fitting portion 231A is accommodated inside the groove 221A and is loosely fitted with the groove 221A.

The annular plate 51 has a plurality of through holes 55 penetrating the mount-side flow 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 the link members 23. The other end 232 of each link member 23 is inserted through the through hole 55 corresponding to each link member 23, and is connected to the variable nozzle vane 21 corresponding to each link member 23.

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

The variable nozzle device 2 can adjust the flow path cross-sectional area of the gas flow path 43A by transmitting the driving force from the driving mechanism 25 to the plurality of variable nozzle vanes 21 via the annular member 22 and the plurality of link members 23, thereby rotating the plurality of variable nozzle vanes 21 about the respective rotation centers RC, and changing the respective vane angles. The turbine 12 can control the supercharging pressure of the turbine 12 by increasing or decreasing the flow path cross-sectional area of the gas flow path 43A by the variable nozzle device 2 to change the flow rate or pressure of the exhaust gas guided to the turbine wheel 3.

(Force applying Member)

In the embodiment shown in fig. 2, the urging member 7 is an annular elastic member (coil spring) disposed in a state compressed in the axial direction between the facing surface 45 of the 2 nd casing 4B and the mount-side back surface 53 of the nozzle mount 5. The urging member 7 receives the reaction force of the urging member 7 through the opposing surface 45, and urges the mount-side back surface 53 toward the other member 100 (the front side). The nozzle mount 5 and the nozzle holder 6 are supported between the urging member 7 and the other member 100 in the axial direction by urging of the urging member 7.

The movement of the nozzle mount 5 and the nozzle holder 6 in the axial direction between the biasing member 7 and the other members 100 in the axial direction is not limited. In the embodiment shown in fig. 2, the 1 st housing 4A has a rear side swirling flow road surface 441 facing the rear side of the scroll flow path 41, and has an inner protruding portion 44 extending inward in the radial direction along the radial direction. The outer peripheral end of the annular plate 51 of the nozzle mount 5 and the inner peripheral end of the inner protruding portion 44 face each other with a gap therebetween, and do not contact the inner protruding portion 44.

In the embodiment shown in fig. 2, the variable nozzle device 2 further includes a positioning pin 56 that restricts movement of the nozzle mount 5 in the radial direction. One end of the positioning pin 56 is inserted into the 1 st hole formed in the mount-side back surface 53 of the nozzle mount 5, and the other end is inserted into the 2 nd hole formed in the surface facing the mount-side back surface 53 of the 2 nd housing 4B. The positioning pin 56 is loosely inserted into at least one of the 1 st hole and the 2 nd hole, and does not restrict the movement of the nozzle mount 5 in the axial direction due to the urging force of the urging member 7, but restricts the movement of the nozzle mount 5 in the radial direction.

In the embodiment shown in fig. 2, the plurality of turbine blades 32 are disposed with a predetermined gap therebetween with respect to the shroud surface 47, which is the inner surface of the 1 st casing 4A. The 1 st housing 4A is formed with an annular recess 48 composed of an outer peripheral surface 481 extending from the outer peripheral end of the shield surface 47 toward the front side in the axial direction and an annular bottom surface 482 extending from the front end of the outer peripheral surface 481 toward the outside in the radial direction. The nozzle plate 8 is inserted into the recess 48.

In the embodiment shown in fig. 2, the 1 st housing 4A has an annular projection 483 projecting to the rear side from the bottom surface 482 on the outer side in the radial direction from the bottom surface 482. The protruding portion 483 has an annular case-side contact surface 484 facing the gas flow path 43A on the rear side. In the nozzle plate 8, the inner peripheral end portion of the nozzle plate 8 faces the outer peripheral surface 481 with a gap therebetween, and the plate-side rear surface 82 abuts against the case-side abutment surface 484. The nozzle plate 8 is biased toward the 1 st housing 4A side in the axial direction by the biasing force of the biasing member 7 via the nozzle holder 6, and is thereby supported between the nozzle holder 6 and the 1 st housing 4A in the axial direction.

(Nozzle holder)

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 invention. The nozzle holder 6 supports two members (the nozzle mount 5 and the nozzle plate 8 in fig. 2) forming the gas flow path 43A in a state of being separated from each other. In the illustrated embodiment, as shown in fig. 2, the variable nozzle device 2 includes a plurality of nozzle holders 6 arranged at intervals in the circumferential direction of the variable nozzle device 2. The plurality of nozzle holders 6 are disposed at positions radially outward of the variable nozzle device 2 than the plurality of variable nozzle vanes 21.

As shown in fig. 4, the plurality of nozzle holders 6 are rod-like members extending along the central axis LD of the nozzle holder 6. As shown in fig. 2, the nozzle holder 6 has a fixing portion 61 fixed to the nozzle mount 5 on one side in the axial direction of the nozzle holder 6, and a main body portion 62 disposed in the gas flow path 43A on the other side in the axial direction of the nozzle holder 6. In the illustrated embodiment, the fixing portion 61 is fixed to the nozzle mount 5 by caulking the fixing portion 61 in the hole 54 formed in the mount-side flow 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 caulking, for example, press-fitting into the nozzle mount 5.

The urging member 7 urges the plurality of nozzle holders 6 toward the other member 100 via the nozzle mount 5. The main body 62 of each of the plurality of nozzle holders 6 has an abutment surface 63 (see fig. 4) against another member 100 forming the gas flow path 43A between the main body and the nozzle mount 5. The abutment surface 63 is an end surface on the opposite side to the side integrally connected to the fixing portion 61 of the main body portion 62. In the embodiment shown in fig. 4, the plurality of nozzle holders 6 extend in a direction parallel to the axis LB along the central axis LD. The abutment surface 63 of each of the plurality of nozzle holders 6 abuts against the plate-side flow surface 81.

In several embodiments, as shown in fig. 4, the plurality of nozzle holders 6 each include the contact surface 63 that contacts the other member 100 and the curved surface 64 whose inner edge is connected to the outer edge of the contact 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 holder 6 in which the curved surface 64 is formed. In the embodiment shown in fig. 4, the curved surface 64 is formed on the main body 62, and the outer edge of the curved surface 64 is connected to the outer surface (outer peripheral surface) 621 of the main body 62.

Fig. 5 is an explanatory diagram for explaining thermal deformation of the variable nozzle device 02 according to the comparative example. Fig. 6 is an explanatory view for explaining thermal deformation of the variable nozzle device 2 according to an embodiment of the present invention. The nozzle holder 06 of the variable nozzle device 02 has a fixing portion 061 fixed to the nozzle mount 5 and a main body portion 062 disposed in the gas flow path 43A. The main body 062 has an abutment surface 063 for abutting 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 062. In addition, the usual degree of R-machining may be applied to the outer edge 0631.

As shown in fig. 5 and 6, thermal deformation may occur in two members (the nozzle mount 5 and the other member 100) forming the gas flow path 43A due to the exhaust gas flowing through the gas flow path 43A, and the nozzle holder 6 may abut against the other member 100 in a state where the central axis LD of the nozzle holder 6 is inclined with respect to the direction parallel to the axis LB due to the difference in thermal deformation between the two members. In the embodiment shown in fig. 5 and 6, thermal deformation occurs in the direction in which the nozzle mount 5 and the other member 100 are away from each other in the axial direction, and the nozzle holder 6 is inclined so that the other member 100 side of the nozzle holder 6 is further away from the axis LB than the nozzle mount 5 side.

In the variable nozzle device 02 according to the comparative example, as shown in fig. 5, if the outer edge 0631 of the contact surface 063 comes into contact with another member 100 due to the thermal deformation, local stress concentration occurs in the outer edge 0631 of the contact surface 063, and there is a possibility that the nozzle holder 6 may be broken or damaged. In contrast, in the variable nozzle device 2 of the present invention, as shown in fig. 6, when the curved surface 64 is in contact with the other member 100 due to the thermal deformation, the stress concentration in the curved surface 64 can be relaxed by the contour shape of the curved surface 64.

According to the above configuration, by providing the curved surface 64 on the nozzle holder 6, the stress concentration at the time of contact of the curved surface 64 of the nozzle holder 6 with the other member 100 due to the difference in thermal deformation occurring between the nozzle mount 5 and the other member 100 can be alleviated. By relaxing the stress concentration of the nozzle holder 6, breakage or damage due to the stress concentration of the nozzle holder 6 can be suppressed.

As shown in fig. 2, the variable nozzle device 2 according to several embodiments includes a nozzle plate 8 having a plate-side flow surface 81 that forms a gas flow path 43A with the nozzle mount 5, and the plate-side flow surface 81 that is in contact with the contact surface 63 of the at least one nozzle holder 6. The other member 100 is constituted by the nozzle plate 8.

According to the above configuration, the stress concentration when the curved surface 64 of the nozzle holder 6 is in contact with the plate-side flow surface 81 due to the difference in thermal deformation occurring between the nozzle mount 5 and the nozzle plate 8 can be alleviated.

The present invention is also applicable to the variable nozzle device 2 without the nozzle plate 8. Fig. 7 is a schematic cross-sectional view taken along the axis LA of the turbine 12 according to an embodiment of the present invention. In the variable nozzle device 2 according to the several embodiments, as shown in fig. 7, the other member 100 is constituted by the housing 4 (1 st housing 4A). The 1 st housing 4A has a housing-side flow surface 491 on which the gas flow path 43A is formed between the nozzle mount 5 and the contact surface 63 of the at least one nozzle holder 6 contacts.

In the embodiment shown in fig. 7, the 1 st casing 4A includes a flow path surface forming portion 49 having a casing-side flow path 491. The case-side flow surface 491 is constituted by an annular surface extending in the circumferential direction and extends in the radial direction. The inner peripheral end of the case-side flow surface 491 is connected to the outer peripheral end of the shroud surface 47, and is connected to the shroud surface 47.

In the variable nozzle device 2 according to the several embodiments, as shown in fig. 4, the at least one nozzle holder 6 satisfies the condition 0.1D1R 1 or less when D1 is the maximum diameter of the outer surface 621 of the nozzle holder 6 and R1 is the radius of curvature of the curved surface 64. Since the curved surface 64 satisfying the condition 0.1D1R 1 is formed to have a gentle contour shape than a machined surface formed by normal R machining, stress concentration at the time of contact between the curved surface 64 of the nozzle holder 6 and the other member 100 can be effectively relaxed.

In the variable nozzle device 2 according to several embodiments, as shown in fig. 4, the at least one nozzle holder 6 includes a constricted portion 65 formed on an outer surface 621 of the nozzle holder 6. The neck portion 65 includes a concave curved surface portion 651 recessed inward in the radial direction as going 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 protruding outward in the radial direction as going from the one side (the nozzle mount 5 side) toward the other side (the other member 100 side).

In several embodiments, as shown in fig. 4, when the radius of curvature of the curved surface 64 is R1, the radius of curvature of the concave curved surface 651 is R2, and the radius of curvature of the convex curved surface 652 is R3, the at least one nozzle holder 6 satisfies the conditions of R1< R2 and R1< R3. In this case, by making the contour shapes of the concave curved surface portion 651 and the convex curved surface portion 652 gentle than the contour shape of the curved surface 64, the occurrence of stress concentration in the constricted portion 65 can be suppressed. The present invention can be applied to a case where the condition of R1< R2 and R1< R3 is not satisfied.

In several embodiments, as shown in fig. 4, when the diameter (maximum diameter) of the contact surface 63 is D2 and the minimum diameter of the neck portion 65 is D3, the at least one nozzle holder 6 satisfies the condition that D2 is equal to or smaller than D3. In this case, since the diameter D2 of the contact surface 63 satisfying the condition that D2D 3 is relatively small, the contour shape of the curved surface 64 can be made gentle compared with the case where the diameter D2 is large, and thus the stress concentration at the time of contact of the curved surface 64 of the nozzle holder 6 with the other member 100 can be effectively relaxed. In addition, the present invention can be applied to a case where the condition d2+.d3 is not satisfied.

As shown in fig. 2 and 7, the turbine 12 according to the several embodiments includes the variable nozzle device 2, the turbine wheel 3, and the casing 4 that accommodates the turbine wheel 3 and the variable nozzle device 2. As shown in fig. 1, the turbocharger 1 according to several embodiments includes the turbine 12 and the centrifugal compressor 13. In this case, the variable nozzle device 2 suppresses damage to the nozzle holder 6, and thereby can improve the reliability of the turbine 12 and the turbocharger 1 including the variable nozzle device 2.

In this specification, the expression "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" and the like means relative or absolute arrangement, and means not only such arrangement in a strict sense but also a state of relative displacement by an angle or distance to such an extent that the same function can be obtained.

For example, expressions such as "identical", "equal", and "homogeneous" that things are in the same state mean not only the same state in a strict sense but also a state in which there is a tolerance or a difference in the degree to which the same function is obtained.

In the present specification, the expression "shape" such as a quadrangle or a cylindrical shape "means not only a shape such as a quadrangle or a cylindrical shape in a geometrically strict sense, but also a shape including a concave-convex portion, a chamfer portion, or the like within a range where the same effect can be obtained.

In the present specification, the expression "including", "including" or "having" one constituent element is not an exclusive expression that excludes the presence of other constituent elements.

The present invention is not limited to the above-described embodiments, and includes modifications to the above-described embodiments or a combination of them as appropriate.

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

1) The variable nozzle device 2 according to at least one embodiment of the present invention is a variable nozzle device 2 housed in a casing 4 together with a turbine wheel 3, the variable nozzle device 2 including:

a nozzle mount 5;

At least one nozzle holder 6 having one side supported by the nozzle mount 5 and the other side abutting against the other member 100, and

The 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 holder 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 holder 6 comprises:

An abutment surface 63 for abutting against the other member 100, and

The curved surface 64 has an inner edge connected to an outer edge of the contact surface 63 and has a contour shape curved in a convex shape in a direction away from the central axis LD of the nozzle holder 6.

According to the configuration of 1) above, by providing the curved surface 64 on the nozzle holder 6, it is possible to alleviate stress concentration when the curved surface 64 of the nozzle holder 6 is in contact with the other member 100 due to the difference in thermal deformation occurring between the nozzle mount 5 and the other member 100. By relaxing the stress concentration of the nozzle holder 6, damage to the nozzle holder 6 can be suppressed.

2) In several embodiments, the variable nozzle device 2 according to 1) above further includes:

A nozzle plate 8 having a plate-side flow surface 81, the plate-side flow surface 81 forming a gas flow path 43A facing the turbine wheel 12 with the nozzle mount 5, the abutment surface 63 of the at least one nozzle holder 6 abutting against the plate-side flow surface 81,

The other part 100 is constituted by the nozzle plate 8.

According to the configuration of 2), the stress concentration when the curved surface 64 of the nozzle holder 6 is in contact with the plate-side flow surface 81 due to the difference in thermal deformation between the nozzle mount 5 and the nozzle plate 8 can be alleviated.

3) In several embodiments, the variable nozzle device 2 according to 1) above, wherein,

The other member 100 is constituted by the casing 4, the casing 4 has a casing-side flow surface 491, the casing-side flow surface 491 forms a gas flow path 43A toward the turbine wheel 12 with the nozzle mount 5 therebetween, and the abutment surface 63 of the at least one nozzle holder 6 abuts against the casing-side flow surface 491.

According to the configuration of 3), the stress concentration when the curved surface 64 of the nozzle holder 6 is in contact with the case-side flow surface 491 due to the difference in thermal deformation caused between the nozzle mount 5 and the case 4 can be alleviated.

4) In several embodiments, the variable nozzle device 2 according to any one of the above 1) to 3), wherein,

Regarding the at least one nozzle holder 6, when D1 is the maximum diameter of the outer surface 621 of the nozzle holder 6 and R1 is the radius of curvature of the curved surface 64, the condition 0.1D1R 1 is satisfied.

According to the configuration of 4), since the curved surface 64 satisfying the condition 0.1D1R 1 has a gentle contour shape compared with the machined surface formed by normal R machining, the stress concentration at the time of contact of the curved surface 64 of the nozzle holder 6 with other members 100 can be effectively relaxed.

5) In several embodiments, the variable nozzle device 2 according to any one of the above 1) to 4), wherein,

The at least one nozzle holder 6 comprises:

a neck portion 65 formed on an outer surface 621 of the nozzle holder 6 and including a concave curved surface portion 651 recessed inward in the radial direction as going from the one side toward the other side and a convex curved surface portion 652 rising outward in the radial direction as going from the one side toward the other side,

When the radius of curvature of the curved surface 64 is R1, the radius of curvature of the concave curved surface 651 is R2, and the radius of curvature of the convex curved surface 652 is R3, the conditions of R1< R2 and R1< R3 are satisfied.

According to the configuration of 5), the occurrence of stress concentration in the constricted portion 65 can be suppressed by making the contour shape of the concave curved portion 651 or the convex curved portion 652 gentle than the contour shape of the curved surface 64.

6) In several embodiments, the variable nozzle device 2 according to any one of the above 1) to 5), wherein,

The at least one nozzle holder 6 comprises:

When the diameter of the contact surface 63 is D2 and the minimum diameter of the constricted portion 65 is D3, the condition that D2 is equal to or smaller than D3 is satisfied.

According to the configuration of 6), since the diameter D2 of the contact surface 63 satisfying the condition that d2+—d3 is relatively small, the contour shape of the curved surface 64 can be made gentle compared with the case where the diameter D2 is large, and thus the stress concentration at the time of contact of the curved surface 64 of the nozzle holder 6 with other members 100 can be effectively relaxed.

7) The turbine 12 according to at least one embodiment of the present invention includes:

The variable nozzle device 2 according to any one of 1) to 6) above;

said turbine wheel 3

The housing 4 accommodates the turbine wheel 3 and the variable nozzle device 2.

According to the configuration of 7), the reliability of the turbine 12 can be improved by suppressing damage to the nozzle holder 6 of the variable nozzle device 2.

8) The turbocharger 1 according to at least one embodiment of the present invention includes:

the turbine 12 according to 7) above, and

The centrifugal compressor 13 is configured to be driven by the turbine 12.

According to the configuration of 8), the reliability of the turbocharger 1 can be improved by suppressing damage to the nozzle holder 6 of the variable nozzle device 2.

Symbol description

1-Turbocharger, 2-variable nozzle device, 3-turbine wheel, 4-housing, 4A-1 st housing, 4B-2 nd housing, 5-nozzle mount, 6-nozzle mount, 7-urging member, 8-nozzle plate, 10-internal combustion engine system, 11-internal combustion engine, 12-turbine, 13-centrifugal compressor, 14-impeller, 15-compressor housing, 16-rotation shaft, 17-bearing, 21-variable nozzle vane, 22-annular member, 23-link member, 25-driving mechanism portion, 31-hub, 32-turbine vane, 41-scroll flow path, 42-exhaust gas discharge flow path, 43-interior space, 43A-gas flow path, 43B-rear side space, 44-inside protrusion, 45-opposing surface, 46, 48-recess, 47-shroud surface, 51-annular plate portion, 52-mount side flow path, 53-mount side back surface, 56-dowel pin, 61, 061-fixing portion, 62, 062-body portion, 63, 063-side abutment surface, 64-neck side back surface, 82-neck side surface, and other side shrinkage surface 100-side surface.

Claims

1. A variable nozzle device housed in a casing together with a turbine wheel, the variable nozzle device comprising:

A nozzle mount;

A biasing member configured to bias the nozzle mount toward the other member,

The at least one nozzle support includes:

An abutment surface abutting the other member, and

2. The variable nozzle device according to claim 1, further comprising:

A nozzle plate having a plate-side flow surface that forms a gas flow path toward the turbine wheel between the nozzle mount and the plate-side flow surface, the abutment surface of the at least one nozzle holder abutting against the plate-side flow surface,

The other components are constituted by the nozzle plate.

3. The variable nozzle device of claim 1, wherein,

The other member is constituted by the housing having a housing side flow surface that forms a gas flow path toward the turbine wheel between the housing side flow surface and the nozzle mount, and the abutment surface of the at least one nozzle holder abuts against the housing side flow surface.

4. A variable nozzle device according to any one of claims 1 to 3, wherein,

Regarding the at least one nozzle holder, when D1 is the maximum diameter of the outer surface of the nozzle holder and R1 is the radius of curvature of the curved surface, the condition 0.1D1R 1 is satisfied.

5. A variable nozzle device according to any one of claims 1 to 3, wherein,

The at least one nozzle support includes:

a neck portion formed on an outer surface of the nozzle holder and including a concave curved surface portion recessed toward an inner side in a radial direction as going from the one side toward the other side and a convex curved surface portion raised toward an outer side in the radial direction as going from the one side toward the other side,

When the radius of curvature of the curved surface is R1, the radius of curvature of the concave curved surface is R2, and the radius of curvature of the convex curved surface is R3, the conditions of R1< R2 and R1< R3 are satisfied.

6. A variable nozzle device according to any one of claims 1 to 3, wherein,

The at least one nozzle support includes:

When the diameter of the contact surface is D2 and the minimum diameter of the neck portion is D3, the condition that D2 is less than or equal to D3 is satisfied.

7. A turbine is provided with:

a variable nozzle device according to any one of claims 1 to 3;

The turbine wheel

The housing accommodates the turbine wheel and the variable nozzle device.

8. A turbocharger provided with the turbine of claim 7 and a centrifugal compressor configured to be driven by the turbine.