JP6756008B2 - Turbocharger - Google Patents

Description

The present disclosure relates to a turbocharger.

A turbocharger is known as a means for increasing the thermal efficiency of an internal combustion engine. In Patent Document 1, "a center core arranged in the center of a scroll portion of a turbocharger is integrally formed of a flow path outlet portion, a bearing fitting portion, and a support column from a steel pipe material, and the scroll portion body is thermally deformed. A turbocharger is disclosed for the purpose of preventing changes in chip clearance due to the above, reducing cost and weight, and improving durability, reliability, and impact resistance of a turbine. "

According to Patent Document 1, by adopting a center core in which a steel material is integrally formed in an annular shape in a turbocharger, the wall thickness can be reduced and the heat capacity is reduced, so that the temperature of the turbine portion rises faster and the exhaust gas on the downstream side is exhausted. The warming of the purification device is promoted, and the purification action of the exhaust gas purification device is efficiently exhibited.

Japanese Unexamined Patent Publication No. 2011-174460

By the way, according to the knowledge of the inventor of the present application, when the turbocharger is operated, the turbine housing forming the scroll flow path undergoes bending deformation (thermal deformation) due to the temperature distribution in the turbine housing. In particular, when the scroll flow path forming portion in the turbine housing is made of sheet metal, large bending deformation is likely to occur.

For example, as shown in FIGS. 7 to 9, when the turbine housing 004 is a housing having a two-layer structure of a first housing 030 made of sheet metal and a second housing 032 made of sheet metal, a scroll flow path 014 is formed. A temperature distribution as shown in FIG. 8 occurs in the first housing 030. As shown in FIG. 8, the first housing 030 tends to have a relatively low temperature on the bearing housing 006 side, and due to this temperature distribution, bending deformation in the direction of arrow A shown in FIGS. 7 and 8 Occurs in the first housing 030.

Therefore, in the turbochargers shown in FIGS. 7 to 9, unless the tip clearance between the shroud, which is a part of the first housing, and the turbine wheel is sufficiently large, the tongue portion of the turbine housing (due to the bending deformation) ( In the case of the two-layer structure, there is a possibility that the shroud comes into contact with the turbine wheel near the position P1 on the side of the winding end portion of the scroll flow path in the first housing.

Therefore, in order to avoid such contact, it is necessary to take a large tip clearance between the turbine wheel and the shroud so that the contact does not occur even if bending deformation occurs, and the loss due to this clearance causes the turbine efficiency. Was hindered from improving.

In this regard, although the turbocharger described in Patent Document 1 is intended to prevent a change in the chip clearance due to thermal deformation of the scroll portion main body, the scroll portion main body is directly connected to the shroud and the scroll is scrolled. The effect of reducing the effect of thermal deformation of the main body on the change in chip clearance was limited. For this reason, it has been difficult to achieve high turbine efficiency while avoiding contact between the turbine wheel and the shroud.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is a turbo that makes it possible to realize high turbine efficiency while avoiding contact between a turbine wheel and a shroud. To provide a charger.

(1) The turbocharger according to at least one embodiment of the present invention accommodates a turbine wheel configured to be rotated by the exhaust gas of the engine and a scroll flow in which the exhaust gas supplied to the turbine wheel flows. A turbine housing that forms at least a portion of the path and a bearing housing that rotatably supports the shaft of the turbine wheel and is connected to the turbine housing are opposed to the tip of a blade of the turbine wheel. A shroud having a surface and configured to surround the turbine wheel, the shroud provided inside the turbine housing with a gap with respect to the turbine housing, and the axial direction of the turbine wheel. A mount supported by at least one of the turbine housing and the bearing housing on the bearing housing side of the scroll flow path, and a connecting portion for connecting the mount and the shroud are provided.

According to the turbocharger described in (1) above, even if the turbine housing is bent and deformed (thermally deformed) due to a temperature distribution caused by the exhaust gas flowing through the scroll flow path, the shroud is a separate component from the turbine housing. The tip clearance between the shroud and the turbine wheel is basically unaffected by the above-mentioned bending deformation of the turbine housing because the turbine housing is provided with a gap. Therefore, even if the tip clearance between the shroud and the turbine wheel is reduced, contact between the shroud and the turbine wheel due to the bending deformation of the turbine housing can be avoided. Therefore, high turbine efficiency can be achieved while avoiding contact between the turbine wheel and the shroud.

(2) In some embodiments, in the turbocharger described in (1) above, each of the connecting portions has a blade shape having a cross-sectional shape perpendicular to the axis of the turbine wheel.

According to the turbocharger described in (2) above, in the turbocharger described in (1) above, the turbocharger flows between the shroud and the mount by a connecting portion having a blade-shaped cross section perpendicular to the axis of the turbine wheel. Since the exhaust gas is rectified, higher turbine efficiency can be achieved.

(3) In some embodiments, the turbocharger according to (1) or (2) above further includes a seal ring that seals the gap between the shroud and the turbine housing.

According to the turbocharger described in (3) above, in the turbocharger described in (1) or (2) above, the leakage of exhaust gas from the gap between the shroud and the turbine housing is suppressed by the seal ring. Can be done. As a result, it is possible to suppress a decrease in turbine efficiency due to leakage of exhaust gas from the gap, so that higher turbine efficiency can be realized.

(4) In some embodiments, in the turbocharger according to any one of (1) to (3) above, the mount is sandwiched between the turbine housing and the bearing housing.

According to the turbocharger described in (4) above, the turbocharger described in (1) to (3) above has a simple configuration by sandwiching the mount between the turbine housing and the bearing housing originally provided in the turbocharger. A charger can be realized.

(5) In some embodiments, in the turbocharger according to (4) above, the mount is an annular flat plate, and the outer peripheral side portion of the mount is sandwiched between the turbine housing and the bearing housing. ing.

According to the turbocharger described in (5) above, by appropriately setting the thickness of the annular flat plate, one side of the annular flat plate can be provided while ensuring the rigidity of the mount for supporting the connection portion and the shroud. It can be used to form part of the scroll flow path. Further, even when a part of the scroll flow path is formed by using one side of the annular flat plate, if the thickness direction of the annular flat plate and the axial direction of the turbine wheel match, the shaft of the turbine wheel Since the amount of thermal elongation of the mount in the direction can be reduced, fluctuations in the tip clearance between the turbine wheel and the shroud can be suppressed.

(6) In some embodiments, in the turbocharger according to (5) above, a bolt for fastening the turbine housing and the bearing housing is further provided, and the outer peripheral side portion of the mount is the axial force of the bolt. It is sandwiched between the turbine housing and the bearing housing.

According to the turbocharger described in (6) above, the mount is attached to the turbine housing and the bearing housing by fastening the turbine housing and the bearing housing with bolts. Therefore, by appropriately setting the fastening force of the bolts, The mount can be fixed to the turbine housing and bearing housing with a simple configuration.

(7) In some embodiments, in the turbocharger according to (4) above, the mount has a tubular portion extending in the axial direction of the turbine wheel and a tubular portion to the tubular portion. The protrusion of the mount includes a protrusion protruding to the outer peripheral side, and the protrusion of the mount is sandwiched between the turbine housing and the bearing housing.

According to the turbocharger described in (7) above, the mount can be sandwiched between the turbine housing and the bearing housing at a position corresponding to the axial length of the tubular portion.

(8) In some embodiments, in the turbocharger according to (7) above, a holding member for connecting the flange provided on the turbine housing and the flange provided on the bearing housing by holding the flange is further provided. The protruding portion of the mount is sandwiched between the turbine housing and the bearing housing by the holding force of the holding member.

According to the turbocharger described in (8) above, the mount is attached to the turbine housing and the bearing housing by sandwiching the turbine housing and the bearing housing with the sandwiching member, so that the sandwiching force of the sandwiching member should be set appropriately. Therefore, the mount can be fixed to the turbine housing and the bearing housing with a simple configuration.

(9) In some embodiments, in the turbocharger according to any one of (1) to (8) above, the mount is an annular member and an annular step portion formed on the bearing housing. Has a fitting portion to be fitted with an inlay.

According to the turbocharger described in (9) above, the axis of the shroud supported by the mount via the connection portion and the axis of the shaft supported by the bearing can be matched with each other in a simple configuration. ..

(10) In some embodiments, the turbocharger according to any one of (1) to (9) above is made of sheet metal that houses the turbine wheel and forms at least a part of the scroll flow path. The first housing is included in the turbine housing, and the shroud is provided inside the first housing with the gap from the first housing.

When the turbine housing includes a first sheet metal housing that houses the turbine wheels and forms at least part of the scroll flow path, compared to the case where the entire turbine housing, including the first housing, is made of metal casting. The first housing is liable to undergo large bending deformation (thermal deformation) due to the influence of exhaust gas flowing through the scroll flow path. In such a case, as described in (10) above, by providing the shroud inside the first housing with a gap with respect to the first housing made of sheet metal, the influence of such bending deformation can be affected by the shroud. Is basically not received. Therefore, even if the tip clearance between the shroud and the turbine wheel is reduced, contact between the shroud and the turbine wheel due to the bending deformation of the first sheet metal housing can be avoided. Therefore, high turbine efficiency can be achieved while avoiding contact between the turbine wheel and the shroud.

(11) In some embodiments, in the turbocharger according to (10) above, the turbine housing is a two-layer housing further comprising a second sheet metal housing for accommodating the first housing.

According to the turbocharger described in (11) above, since the turbine housing is a housing having a two-layer structure, even if the turbine wheel is damaged for some reason and debris is scattered, as compared with the case of the one-layer structure. , It is possible to more reliably prevent the scattering of debris to the outside of the turbine housing 4.

(12) In some embodiments, in the turbocharger according to (11) above, an outlet guide tube integrally formed with the second housing so as to guide the exhaust gas that has passed through the turbine wheel. A piston ring that seals the gap between the first housing and the outlet guide cylinder is further provided so that the first housing can slide in the axial direction of the turbine wheel with respect to the outlet guide cylinder.

When the turbine housing is a two-layer housing including the first housing and the second housing as described in (11) above, the first housing forming at least a part of the scroll flow path is the first housing. 2 The temperature rises relatively compared to the housing, and the amount of heat elongation increases. Therefore, if no measures are taken, stress may be concentrated on the connecting portion between the first housing and the second housing, resulting in damage. Therefore, in the turbocharger described in (12) above, the first housing and the exit guide are provided so that the first housing can slide in the axial direction with respect to the outlet guide cylinder integrally formed with the second housing. It is equipped with a piston ring that seals the gap between the cylinders. As a result, it is possible to prevent damage caused by the difference in the amount of heat elongation between the first housing and the second housing while suppressing leakage of exhaust gas from the gap between the first housing and the outlet guide cylinder.

(13) In some embodiments, in the turbocharger according to (10) above, the turbine housing is a housing having a one-layer structure, and the plate thickness of the shroud is larger than the plate thickness of the first housing. ..

Even when the turbine housing has a one-layer structure as described in (13) above, the plate thickness of the first housing is shrouded by making the plate thickness of the shroud larger than the plate thickness of the first housing. When the turbine wheel is damaged, the fragments of the turbine wheel can be effectively received with less material as compared with the case where the thickness is larger than the thickness of the above.

(14) In some embodiments, in the turbocharger described in (13) above, the plate thickness of the shroud is at least twice the plate thickness of the first housing.

According to the turbocharger described in (14) above, when the turbine wheel is damaged, the turbine wheel debris can be reduced with less material as compared with the case where the plate thickness of the first housing is made larger than the plate thickness of the shroud. It can be taken effectively.

Further, the turbocharger according to at least one embodiment of the present invention is
A turbine wheel that is configured to rotate with the exhaust gas of the engine,
A turbine housing that houses the turbine wheel and forms at least a portion of a scroll flow path through which exhaust gas supplied to the turbine wheel flows.
A bearing housing that houses a bearing that rotatably supports the shaft of the turbine wheel and is connected to the turbine housing.
A shroud having a facing surface facing the tip of a blade of the turbine wheel and configured to surround the turbine wheel, which is composed of a separate part from the turbine housing and with respect to the turbine housing. With a shroud provided inside the turbine housing with a gap,
A mount supported by at least one of the turbine housing and the bearing housing on the bearing housing side of the scroll flow path in the axial direction of the turbine wheel.
At least one connection that connects the mount and the shroud, and at least one connection that is fixed to each of the mount and the shroud.
With
The turbine housing includes a first sheet metal housing that houses the turbine wheels and forms at least a portion of the scroll flow path.
The shroud is provided inside the first housing with the gap with respect to the first housing, and is provided.
Each of the connecting portions has a blade shape in a cross-sectional shape perpendicular to the axis of the turbine wheel, and a bolt for fixing to the mount or the shroud is not penetrated inside the connecting portion.

Further, the turbocharger according to at least one embodiment of the present invention is
A turbine wheel that is configured to rotate with the exhaust gas of the engine,
A turbine housing that houses the turbine wheel and forms at least a portion of a scroll flow path through which exhaust gas supplied to the turbine wheel flows.
A bearing housing that houses a bearing that rotatably supports the shaft of the turbine wheel and is connected to the turbine housing.
A shroud having a facing surface facing the tip of a blade of the turbine wheel and configured to surround the turbine wheel, which is composed of a separate part from the turbine housing and with respect to the turbine housing. With a shroud provided inside the turbine housing with a gap,
A mount supported by at least one of the turbine housing and the bearing housing on the bearing housing side of the scroll flow path in the axial direction of the turbine wheel.
At least one connection that connects the mount and the shroud, and at least one connection that is fixed to each of the mount and the shroud.
With
The turbine housing includes a first sheet metal housing that houses the turbine wheels and forms at least a portion of the scroll flow path.
The shroud is provided inside the first housing with the gap with respect to the first housing, and is provided.
Each of the connecting portions has a blade shape having a cross-sectional shape perpendicular to the axis of the turbine wheel.
The sheet metal first housing has a convex portion that is folded back so as to project toward the mount in the radial direction with respect to the scroll flow path.
The entire radial outer peripheral end surface of the shroud is provided so as to be located radially inside the convex portion of the first housing and radially outside the front edge of the blade of the turbine wheel. Was done.

According to at least one embodiment of the present invention, there is provided a turbocharger that makes it possible to achieve high turbine efficiency while avoiding contact between the turbine wheel and the shroud.

It is a figure which shows typically the cross-sectional structure of the turbocharger 100A which concerns on one Embodiment. It is a figure which shows typically the cross-sectional structure of the turbocharger 100B which concerns on one Embodiment. It is a figure which shows typically the cross-sectional structure of the turbocharger 100C which concerns on one Embodiment. It is a figure which shows typically the cross-sectional structure of the turbocharger 100D which concerns on one Embodiment. It is a figure which shows an example of the cross-sectional shape which is perpendicular to the axis O1 of the turbine wheel 2 in the connection part 12 shown in FIGS. 1 to 4. It is a figure which shows an example of the cross-sectional shape which is perpendicular to the axis O1 of the turbine wheel 2 in the connection part 12 shown in FIGS. 1 to 4. It is a figure which shows typically the cross-sectional structure of the turbocharger which concerns on one reference form. It is a figure which shows the temperature distribution of the inner casing 030 at the time of operation of the turbocharger shown in FIG. It is a figure which shows typically the cross-sectional structure perpendicular to the axis of the turbine housing 004 shown in FIG.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, and are merely explanatory examples. Absent.
For example, expressions that represent relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" are exact. Not only does it represent such an arrangement, but it also represents a state of relative displacement with tolerances or angles and distances to the extent that the same function can be obtained.
For example, expressions such as "same", "equal", and "homogeneous" that indicate that things are in the same state not only represent exactly the same state, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the state of existence.
For example, an expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also an uneven portion or chamfering within a range in which the same effect can be obtained. The shape including the part and the like shall also be represented.
On the other hand, the expressions "equipped", "equipped", "equipped", "included", or "have" one component are not exclusive expressions that exclude the existence of other components.

FIG. 1 is a diagram schematically showing a cross-sectional configuration of a turbocharger 100A according to an embodiment. FIG. 2 is a diagram schematically showing a cross-sectional configuration of the turbocharger 100B according to the embodiment. FIG. 3 is a diagram schematically showing a cross-sectional configuration of the turbocharger 100C according to the embodiment. FIG. 4 is a diagram schematically showing a cross-sectional configuration of the turbocharger 100D according to the embodiment.

In some embodiments, for example, as shown in FIGS. 1-4, the turbocharger 100 (100A-100D) comprises a turbine wheel 2, a turbine housing 4, a bearing housing 6, a shroud 8, a mount 10 and at least one connection. A unit 12 is provided.

In the turbochargers 100 (100A to 100D) shown in FIGS. 1 to 4, the turbine wheel 2 is configured to be rotated by the exhaust gas of an engine (not shown). The turbine housing 4 accommodates the turbine wheel 2 and forms at least a part of the scroll flow path 14 through which the exhaust gas supplied to the turbine wheel 2 flows. The bearing housing 6 accommodates a bearing 18 that rotatably supports the shaft 16 of the turbine wheel 2, and is connected to the turbine housing 4. The shroud 8 has an facing surface 8a facing the tip 20a of the blade 20 of the turbine wheel 2, and is configured to surround the turbine wheel 2. Further, the shroud 8 is formed of a separate component from the turbine housing 4 and is provided inside the turbine housing 4 with a gap 22 with respect to the turbine housing 4. The mount 10 is supported by at least one of the turbine housing 4 and the bearing housing 6 on the bearing housing 6 side of the scroll flow path 14 in the axial direction of the turbine wheel 2. Each of at least one connecting portion 12 (a plurality of connecting portions 12 in the form shown in FIGS. 1 to 4) is configured to connect the mount 10 and the shroud 8.

As described above, according to the turbocharger 100 (100A to 100D), even if the turbine housing 4 is bent and deformed (thermally deformed) due to the temperature distribution caused by the exhaust gas flowing through the scroll flow path 14, the shroud 8 Is composed of a separate part from the turbine housing 4 and is provided with a gap 22 with respect to the turbine housing 4, so that the tip clearance between the shroud 8 and the turbine wheel 2 (opposing surface 8a and tip 20a) is provided. The clearance with the turbine housing 4) is basically unaffected by the bending deformation of the turbine housing 4. Therefore, even if the tip clearance between the shroud 8 and the turbine wheel 2 is reduced, the contact between the shroud 8 and the turbine wheel 2 due to the bending deformation of the turbine housing 4 can be avoided. Therefore, high turbine efficiency can be realized while avoiding contact between the turbine wheel 2 and the shroud 8.

In some embodiments, the turbine housing 4 comprises a sheet metal first housing 30 that accommodates the turbine wheels 2 and forms at least a portion of the scroll flow path 14, as shown, for example, FIGS. The shroud 8 is provided inside the first housing 30 with a gap 22 with respect to the first housing 30.

In such a configuration, as compared with the case where the entire turbine housing 4 including the first housing 30 is made of cast metal, since the first housing 30 is made of sheet metal, it is affected by the exhaust gas flowing through the scroll flow path 14. Large bending deformation (thermal deformation) is likely to occur in the first housing 30. Even in such a case, since the shroud 8 is provided inside the first housing 30 with a gap 22 with respect to the first housing 30 made of sheet metal, the turbine wheel 2 and the shroud 8 are provided as described above. High turbine efficiency can be achieved while avoiding contact with.

In some embodiments, for example, as shown in FIGS. 1 and 2, the turbine housing 4 is a two-layer housing further comprising a second housing 32 made of sheet metal that houses the first housing 30.

In such a configuration, since the turbine housing is a housing having a two-layer structure, even if the turbine wheel 2 is damaged for some reason and debris is scattered, it can be moved to the outside of the turbine housing 4 as compared with the case of the one-layer structure. It is possible to prevent the scattering of debris more reliably.

In some embodiments, for example, as shown in FIGS. 1 and 2, the turbocharger 100 (100A, 100B) further comprises an outlet guide tube 34 and a piston ring 36. The outlet guide cylinder 34 is configured to guide the exhaust gas that has passed through the turbine wheel 2, and is joined to the outlet flange 35 of the turbine casing 4. The outlet flange 35 is joined to the second housing 32 by, for example, welding, and the second housing 32 and the outlet guide cylinder 34 are integrally formed together with the outlet flange 35. The piston ring 36 is configured to seal the gap 38 between the first housing 30 and the outlet guide cylinder 34 so that the first housing 30 can slide in the axial direction of the turbine wheel 2 with respect to the outlet guide cylinder 34. There is.

When the turbine housing 4 is a housing having a two-layer structure including the first housing 30 and the second housing 32 as shown in FIGS. 1 and 2, the first housing forming at least a part of the scroll flow path 14. The temperature of 30 is relatively higher than that of the second housing 32, and the amount of heat elongation is larger. Therefore, if no measures are taken, stress may be concentrated on the connecting portion between the first housing 30 and the second housing 32, causing damage. In this regard, in the turbochargers 100 (100A, 100B) shown in FIGS. 1 and 2, the first housing 30 is the axis with respect to the outlet guide cylinder 34 integrally formed with the second housing 32 as described above. A piston ring 36 that seals the gap 38 between the first housing 30 and the outlet guide cylinder 34 is provided so as to be slidable in the direction. As a result, while suppressing the leakage of exhaust gas from the gap 38 between the first housing 30 and the outlet guide cylinder 34, damage due to the difference in the amount of heat elongation between the first housing 30 and the second housing 32 is avoided. be able to.

In some embodiments, for example, as shown in FIGS. 3 and 4, the turbine housing 4 is a one-layer housing, and the shroud 8 has a plate thickness greater than that of the first housing 30.

Even when the turbine housing 4 is a housing having a one-layer structure, the plate thickness of the shroud 8 is made larger than the plate thickness of the first housing 30 so that the plate thickness of the first housing 30 is increased. When the turbine wheel 2 is damaged, the fragments of the turbine wheel 2 can be effectively received with a small amount of material as compared with the case where the thickness is larger than the plate thickness. It is desirable that the plate thickness of the shroud 8 is at least twice the plate thickness of the first housing 30.

In some embodiments, for example, as shown in FIGS. 1 to 4, the turbine housing 4 has an annular structural portion 33 adjacent to the bearing housing 6, and the mount 10 is of the turbine housing 4. It is sandwiched between the structural portion 33 and the bearing housing 6. Regarding the structural portion 33, in the turbine housing 4 having a two-layer structure shown in FIGS. 1 and 2, the annular structural portion 33 is, for example, a casting, and the first housing 30 made of sheet metal and the second housing 32 made of sheet metal May be joined by welding or the like. Further, in the turbine housing 4 having a one-layer structure shown in FIGS. 3 and 4, the annular structural portion 33 is, for example, a casting, and may be joined to the first housing 30 by welding or the like.

As described above, in the turbochargers 100 (100A to 100D) shown in FIGS. 1 to 4, the mount 10 is sandwiched between the turbine housing 4 and the bearing housing 6 inherently provided in the turbocharger, so that the mount 10 can be mounted with a simple configuration. 10 can be fixed.

In some embodiments, for example, in the turbochargers 100 (100A, 100C) shown in FIGS. 1 and 3, the mount 10 is an annular flat plate, and the outer peripheral portion 10a of the mount 10 is a turbine housing 4 and a bearing housing. It is sandwiched between 6 and 6.

In this case, by appropriately setting the thickness of the annular flat plate, the rigidity of the mount 10 for supporting the shroud 8 via the connecting portion 12 is ensured, and the scroll flow is performed by using one side 10f of the mount 10. A part of the road 14 can be formed. Further, even when a part of the scroll flow path 14 is formed by using one side 10f of the mount 10, if the thickness direction of the mount 10 and the axial direction of the turbine wheel 2 match, the turbine wheel 2 Since the amount of thermal elongation of the mount 10 in the axial direction of the turbine wheel 2 can be reduced, fluctuations in the chip clearance between the turbine wheel 2 and the shroud 8 can be suppressed.

In some embodiments, for example, as shown in FIGS. 1 and 3, the turbocharger 100 (100A, 100C) further comprises a bolt 26 for fastening the structural portion 33 of the turbine housing 4 to the bearing housing 6. .. In this case, the outer peripheral side portion 10a of the mount 10 is sandwiched between the structural portion 33 of the turbine housing 4 and the bearing housing 6 by the axial force of the bolt 26.

In this way, since the mount 10 is attached to the turbine housing 4 and the bearing housing 6 by fastening the turbine housing 4 and the bearing housing 6 with the bolts 26, it is easy to set the fastening force of the bolts 26 appropriately. The mount 10 can be fixed to the turbine housing 4 and the bearing housing 6 in the configuration.

In some embodiments, for example, as shown in FIGS. 2 and 4, the mount 10 has a tubular portion 10b extending in the axial direction of the turbine wheel 2 and an outer peripheral side from the tubular portion 10b to the tubular portion 10b. Includes an annular protrusion 10c that protrudes into the. In this case, the protruding portion 10c of the mount 10 is sandwiched between the turbine housing 4 and the bearing housing 6. As a result, the mount 10 can be sandwiched between the turbine housing 4 and the bearing housing 6 at a position corresponding to the axial length of the tubular portion 10b.

In some embodiments, for example, as shown in FIGS. 2 and 4, the turbocharger 100 (100B, 100D) is a flange 40 provided in the structural portion 33 of the turbine housing 4 and a flange provided in the bearing housing 6. A sandwiching member 28 that is connected to the 42 by sandwiching the 42 is further provided. In this case, the protruding portion 10c of the mount 10 is sandwiched between the structural portion 33 of the turbine housing 4 and the bearing housing 6 by the sandwiching force of the sandwiching member 28. The sandwiching member 28 may be, for example, a C ring having a C-shaped cross section.

In this way, by connecting the flange of the turbine housing 4 and the flange of the bearing housing 6 with the holding member 28, the mount 10 is attached to the turbine housing 4 and the bearing housing 6, so that the holding force of the holding member 28 is appropriately set. By doing so, the mount 10 can be fixed to the turbine housing 4 and the bearing housing 6 with a simple configuration.

In some embodiments, for example, as shown in FIGS. 1 to 4, the mount 10 is an annular member, and a fitting portion 10d that is fitted with an annular step portion 6a formed in the bearing housing 6 by inlay is provided. Have. As a result, the axis O2 of the shroud 8 supported by the mount 10 via the connecting portion 12 and the axis O1 of the shaft 16 supported by the bearing 18 can be matched with each other in a simple configuration.

In some embodiments, the turbocharger 100 (100A-100D) further comprises a back plate 23, for example as shown in FIGS. 1-4. The back plate 23 is provided to seal the exhaust gas leaking from the inlet of the turbine wheel 5 and flowing to the back side of the turbine wheel 5 and to shield the heat from being transferred to the bearing side. The outer peripheral end of the back plate 23 is supported by an annular step portion 10e provided on the inner peripheral surface of the mount 10, and the inner peripheral end of the back plate is supported by the annular step portion 6b of the bearing housing 6. Has been done. The annular step portion 6b is provided on the inner peripheral side of the annular step portion 6a.

In some embodiments, for example, as shown in FIGS. 1-4, the turbocharger 100 (100A-100D) further comprises a seal ring 24 that seals the gap 22 between the shroud 8 and the first housing 30. It is desirable that the seal ring 24 has enough elasticity to maintain the seal of the gap between the shroud 8 and the first housing 30 even if the first housing 30 is thermally deformed. For example, as shown in FIGS. 1 to 4. Those having a C-shaped cross section may be used, an O-ring may be used, or another shape may be used.

As a result, the leakage of exhaust gas from the gap 22 between the shroud 8 and the first housing 30 can be suppressed by the seal ring 24. Therefore, it is possible to suppress a decrease in turbine efficiency due to leakage of exhaust gas from the gap 22 and realize higher turbine efficiency.

FIG. 5 is a diagram showing an example of a cross-sectional shape perpendicular to the axis O1 of the turbine wheel 2 in the connection portion 12 shown in FIGS. 1 to 4. FIG. 6 is a diagram showing another example of the cross-sectional shape perpendicular to the axis O1 of the turbine wheel 2 in the connection portion 12 shown in FIGS. 1 to 4.

In some embodiments, as shown in FIG. 5, each of the connecting portions 12 has a blade shape in cross section perpendicular to the axis of the turbine wheel 2. In the illustrated embodiment, the blade-shaped front edge portion (upstream side of the exhaust gas flow) has a trailing edge portion (exhaust gas) so as to follow the flow direction of the exhaust gas flowing through the scroll flow path 14 and flowing into the turbine wheel 2. It is configured to be located radially outside (downstream of the gas flow). As a result, the exhaust gas flowing between the shroud 8 and the mount 10 is rectified by the connecting portion 12 having a blade-shaped cross section perpendicular to the shaft O1 of the turbine wheel 2, so that higher turbine efficiency can be realized. Can be done.

In some embodiments, as shown in FIG. 6 (reference example) , each of the connecting portions 12 has a circular cross-sectional shape perpendicular to the axis of the turbine wheel 2. As a result, the shroud 8 and the mount 10 can be connected with a simple configuration.

The present invention is not limited to the above-described embodiment, and includes a modification of the above-described embodiment and a combination of these embodiments as appropriate.

2 Turbine wheel 4 Turbine housing 6 Bearing housing 6a Step 6b Step 8 Shroud 8a Opposing surface 10 Mount 10a Outer peripheral side 10b Cylindrical part 10c Protruding part 10d Fitting part 10e Step part 10f One side 12 Connection part 14 Scroll flow path 16 Shaft 18 Bearing 20 Blade 20a Tip 22 Gap 23 Back plate 24 Seal ring 26 Bolt 28 Holding member 30 1st housing 32 2nd housing 33 Structural part 34 Exit guide cylinder 35 Outlet flange 36 Piston ring 38 Gap 40 Flange 42 Flange 100 (100A) , 100B, 100C, 100D) Turbocharger

Claims (11)

A turbine wheel that is configured to rotate with the exhaust gas of the engine,
A turbine housing that houses the turbine wheel and forms at least a portion of a scroll flow path through which exhaust gas supplied to the turbine wheel flows.
A bearing housing that houses a bearing that rotatably supports the shaft of the turbine wheel and is connected to the turbine housing.
A shroud having a facing surface facing the tip of a blade of the turbine wheel and configured to surround the turbine wheel, which is composed of a separate part from the turbine housing and with respect to the turbine housing. With a shroud provided inside the turbine housing with a gap,
A mount supported by at least one of the turbine housing and the bearing housing on the bearing housing side of the scroll flow path in the axial direction of the turbine wheel.
At least one connection that connects the mount and the shroud, and at least one connection that is fixed to each of the mount and the shroud.
With
The turbine housing includes a first sheet metal housing that houses the turbine wheels and forms at least a portion of the scroll flow path.
The shroud is provided inside the first housing with the gap with respect to the first housing, and is provided.
Each of the connecting portions has a blade shape in a cross-sectional shape perpendicular to the axis of the turbine wheel, and a bolt for fixing to the mount or the shroud is not penetrated inside the connecting portion .
The mount is a turbocharger sandwiched between the turbine housing and the bearing housing . A turbine wheel that is configured to rotate with the exhaust gas of the engine,
A turbine housing that houses the turbine wheel and forms at least a portion of a scroll flow path through which exhaust gas supplied to the turbine wheel flows.
A bearing housing that houses a bearing that rotatably supports the shaft of the turbine wheel and is connected to the turbine housing.
A shroud having a facing surface facing the tip of a blade of the turbine wheel and configured to surround the turbine wheel, which is composed of a separate part from the turbine housing and with respect to the turbine housing. With a shroud provided inside the turbine housing with a gap,
A mount supported by at least one of the turbine housing and the bearing housing on the bearing housing side of the scroll flow path in the axial direction of the turbine wheel.
At least one connection that connects the mount and the shroud, and at least one connection that is fixed to each of the mount and the shroud.
With
The turbine housing includes a first sheet metal housing that houses the turbine wheels and forms at least a portion of the scroll flow path.
The shroud is provided inside the first housing with the gap with respect to the first housing, and is provided.
Each of the connecting portions has a blade shape having a cross-sectional shape perpendicular to the axis of the turbine wheel.
The sheet metal first housing has a convex portion that is folded back so as to project toward the mount in the radial direction with respect to the scroll flow path.
The entire radial outer peripheral end surface of the shroud is provided so as to be located radially inside the convex portion of the first housing and radially outside the front edge of the blade of the turbine wheel. Turbocharger. The turbocharger according to claim 1 or 2, further comprising a seal ring for sealing the gap between the shroud and the turbine housing. The mount is an annular flat plate and
The turbocharger according to claim 1 , wherein the outer peripheral side portion of the mount is sandwiched between the turbine housing and the bearing housing. Further provided with bolts for fastening the turbine housing and the bearing housing.
The turbocharger according to claim 4 , wherein the outer peripheral side portion of the mount is sandwiched between the turbine housing and the bearing housing by the axial force of the bolt. The mount includes a tubular portion extending in the axial direction of the turbine wheel and a protruding portion protruding from the tubular portion toward the outer peripheral side of the tubular portion.
The turbocharger according to claim 1 , wherein the protruding portion of the mount is sandwiched between the turbine housing and the bearing housing. Further provided with a holding member for connecting the flange provided on the turbine housing and the flange provided on the bearing housing by holding the flange.
The turbocharger according to claim 6 , wherein the protruding portion of the mount is sandwiched between the turbine housing and the bearing housing by the holding force of the holding member. A turbine wheel that is configured to rotate with the exhaust gas of the engine,
A turbine housing that houses the turbine wheel and forms at least a portion of a scroll flow path through which exhaust gas supplied to the turbine wheel flows.
A bearing housing that houses a bearing that rotatably supports the shaft of the turbine wheel and is connected to the turbine housing.
A shroud having a facing surface facing the tip of a blade of the turbine wheel and configured to surround the turbine wheel, which is composed of a separate part from the turbine housing and with respect to the turbine housing. With a shroud provided inside the turbine housing with a gap,
A mount supported by at least one of the turbine housing and the bearing housing on the bearing housing side of the scroll flow path in the axial direction of the turbine wheel.
At least one connection that connects the mount and the shroud, and at least one connection that is fixed to each of the mount and the shroud.
With
The turbine housing includes a first sheet metal housing that houses the turbine wheels and forms at least a portion of the scroll flow path.
The shroud is provided inside the first housing with the gap with respect to the first housing, and is provided.
Each of the connecting portions has a blade shape in a cross-sectional shape perpendicular to the axis of the turbine wheel, and a bolt for fixing to the mount or the shroud is not penetrated inside the connecting portion.
The mount is an annular member, Ruta Bochaja that having a fitting portion fitted with spigot to the annular step portion formed in the bearing housing. A turbine wheel that is configured to rotate with the exhaust gas of the engine,
A turbine housing that houses the turbine wheel and forms at least a portion of a scroll flow path through which exhaust gas supplied to the turbine wheel flows.
A bearing housing that houses a bearing that rotatably supports the shaft of the turbine wheel and is connected to the turbine housing.
A shroud having a facing surface facing the tip of a blade of the turbine wheel and configured to surround the turbine wheel, which is composed of a separate part from the turbine housing and with respect to the turbine housing. With a shroud provided inside the turbine housing with a gap,
A mount supported by at least one of the turbine housing and the bearing housing on the bearing housing side of the scroll flow path in the axial direction of the turbine wheel.
At least one connection that connects the mount and the shroud, and at least one connection that is fixed to each of the mount and the shroud.
With
The turbine housing includes a first sheet metal housing that houses the turbine wheels and forms at least a portion of the scroll flow path.
The shroud is provided inside the first housing with the gap with respect to the first housing, and is provided.
Each of the connecting portions has a blade shape in a cross-sectional shape perpendicular to the axis of the turbine wheel, and a bolt for fixing to the mount or the shroud is not penetrated inside the connecting portion.
The turbine housing has a two-layer structure including a second housing made of sheet metal for accommodating the first housing.
An outlet guide tube integrally formed with the second housing so as to guide the exhaust gas that has passed through the turbine wheel.
As the first housing is slidable in the axial direction of the turbine wheel with respect to the exit guide tube, further comprising filter Bochaja and a piston ring for sealing the gap of the exit guide tube and the first housing .. The turbocharger according to claim 1, wherein the turbine housing has a one-layer structure, and the plate thickness of the shroud is larger than the plate thickness of the first housing. The turbocharger according to claim 10 , wherein the plate thickness of the shroud is at least twice the plate thickness of the first housing.