JP2021173175A - Turbine housing - Google Patents

Abstract

To provide a turbine housing capable of restraining condensate water from gathering at a gap between an exterior member and an interior member.SOLUTION: A scroll flow passage forming plate 60 has a scroll communication portion H1. The scroll communication portion H1 communicates a scroll gap 65 and a turbine scroll flow passage 35. Even when condensate water W is generated in the scroll gap 65, the condensate water W is discharged to the turbine scroll flow passage 35 from the scroll gap 65 through the scroll communication portion H1. The condensate water W discharged to the turbine scroll flow passage 35 from the scroll gap 65 through the scroll communication portion H1 flows through the turbine scroll flow passage 35 together with exhaust gas flowing through the turbine scroll flow passage 35, or is evaporated by heat of the exhaust gas, and therefore, the condensate water W is restrained from gathering at the scroll gap 65.SELECTED DRAWING: Figure 2

Description

The present invention relates to a turbine housing.

Conventionally, as a turbine housing of a turbocharger, a turbine housing having a double structure is known. For example, a turbine housing as disclosed in Patent Document 1 is formed of an interior member and an exterior member that accommodates the interior member via a gap portion. The interior member forms at least an inner wall of a spiral scroll passage that is part of the exhaust passage through which the exhaust gas discharged from the engine flows and is formed so as to surround the turbine wheel.

Japanese Unexamined Patent Publication No. 2016-108974

By the way, the exhaust gas discharged from the engine contains water vapor. Here, the interior member is warmed by the heat of the exhaust gas, but since a gap is formed between the interior member and the exterior member, it is difficult to transfer heat from the interior member to the exterior member. .. Therefore, there is a temperature difference between the exterior member and the interior member, and the temperature of the exterior member is lower than that of the interior member. At this time, for example, when the exhaust gas flows into the gap between the exterior member and the interior member, the exhaust gas is cooled by heat exchange between the exhaust gas flowing into the gap and the exterior member, and the exhaust gas is contained in the exhaust gas. The water vapor contained in the air may condense to generate condensed water in the voids. If the condensed water generated in this way collects in the voids, it may cause corrosion of the exterior member and the interior member.

An object of the present invention has been made to solve the above problems, and an object of the present invention is to provide a turbine housing capable of suppressing accumulation of condensed water in a gap between an exterior member and an interior member. To do.

The turbine housing that solves the above problems is an interior member that is a part of the exhaust passage through which the exhaust gas discharged from the engine flows and at least forms the inner wall of the spiral scroll passage formed so as to surround the turbine wheel. A turbine housing formed by an exterior member for accommodating the interior member via a gap portion, and the interior member has a communication portion for communicating the gap portion and the exhaust passage.

According to this, for example, the exhaust gas flows into the gap between the exterior member and the interior member, and heat exchange is performed between the exhaust gas flowing into the gap and the exterior member to cool the exhaust gas. Even if the water vapor contained in the exhaust gas condenses to generate condensed water in the voids, the condensed water can be discharged from the voids to the exhaust passage through the communication portion. Then, the condensed water discharged from the gap portion to the exhaust passage through the communication portion flows through the exhaust passage together with the exhaust gas flowing through the exhaust passage and evaporates due to the heat of the exhaust gas, so that it is between the exterior member and the interior member. It is possible to prevent the condensed water from accumulating in the voids of the.

In the turbine housing, the communication portion may be formed at a portion of the interior member located vertically below the axis of the turbine wheel extending in the horizontal direction.

When condensed water is generated in the gap, the condensed water generated in the gap flows downward in the vertical direction through the gap due to its own weight. At this time, since the communication portion is formed in the portion of the interior member located vertically below the axis of the turbine wheel extending in the horizontal direction, the condensed water that flows downward in the vertical direction through the gap due to its own weight. Is easily discharged from the gap portion to the exhaust passage through the communication portion. Therefore, the condensed water generated in the gap portion can be efficiently discharged from the gap portion to the exhaust passage through the communication portion, and it is possible to easily suppress the accumulation of the condensed water in the gap portion.

In the turbine housing, the exterior member includes a bottomed tubular housing main body having a plate-shaped bottom wall and a peripheral wall erected in a cylindrical shape from the outer peripheral portion of the bottom wall, and the housing main body. The interior member has a scroll flow path forming plate that forms an inner wall of the scroll flow path on the housing main body side, and the gap portion has a closing member that closes the opening of the peripheral wall. It is preferable that the scroll gap portion formed between the housing main body portion and the scroll flow path forming plate is included, and the communication portion includes a scroll communication portion that communicates the scroll gap portion and the scroll flow path.

Exhaust gas flows into the scroll gap formed between the housing main body and the scroll flow path forming plate, and heat is exchanged between the exhaust gas flowing into the scroll gap and the housing main body, so that the exhaust gas is discharged. When cooled, the water vapor contained in the exhaust gas may condense to generate condensed water in the scroll voids. Even in this case, the condensed water can be discharged from the scroll gap portion to the scroll flow path via the scroll communication portion. Then, the condensed water discharged from the scroll gap portion to the scroll flow path via the scroll communication portion flows through the scroll flow path together with the exhaust gas flowing through the scroll flow path, or evaporates due to the heat of the exhaust gas, so that the housing main body portion It is possible to prevent condensed water from accumulating in the scroll gap between the scroll flow path forming plate and the scroll flow path forming plate.

In the turbine housing, the scroll communication portion may be formed at the lowermost portion of the scroll flow path forming plate.
Since the condensed water generated in the scroll gap portion flows downward in the vertical direction in the scroll gap portion due to its own weight, the condensed water generated in the sucrose gap portion tends to collect at the bottom of the scroll gap portion. At this time, since the scroll communication portion is formed at the lowermost portion of the scroll flow path forming plate, the condensed water collected at the lowermost portion of the scroll gap portion is discharged from the scroll gap portion to the scroll flow path via the scroll communication portion. Easy to do. Therefore, the condensed water generated in the scroll gap can be efficiently discharged from the scroll gap to the scroll flow path via the scroll communication portion, and it is possible to easily prevent the condensed water from accumulating in the scroll gap.

In the turbine housing, the scroll gap portion is a gap reduction in which the distance between the inner peripheral surface of the housing main body and the outer peripheral surface of the scroll flow path forming plate gradually becomes shorter as the distance between the scroll communication portion approaches the scroll communication portion. It is good to have a part.

According to this, the volume of the portion vertically lower than the scroll communication portion in the scroll gap portion is smaller than that in the configuration in which the sucrose gap portion does not have the gap reduction portion. Therefore, the condensed water collected at the bottom of the scroll gap portion is more likely to be discharged from the scroll gap portion to the scroll flow path via the scroll communication portion. Therefore, the condensed water generated in the scroll gap can be more efficiently discharged from the scroll gap to the scroll flow path via the scroll communication portion, and it is easier to prevent the condensed water from accumulating in the scroll gap. can.

In the turbine housing, the interior member has a tubular introduction flow path forming plate that is a part of the exhaust passage and forms an inner wall of the introduction flow path for introducing the exhaust gas into the scroll flow path. The exterior member has a tubular introduction portion forming portion for accommodating the introduction flow path forming plate, and the gap portion is an introduction portion formed between the introduction portion forming portion and the introduction flow path forming plate. The communication portion may include a gap portion, and the communication portion may include an introduction portion communication portion that communicates the introduction portion gap portion with the exhaust passage.

Exhaust gas flows into the introduction portion gap formed between the introduction portion forming portion and the introduction flow path forming plate, and heat exchange is performed between the exhaust gas flowing into the introduction portion gap and the introduction portion forming portion. As a result, the exhaust gas may be cooled, and the water vapor contained in the exhaust gas may be condensed to generate condensed water in the voids of the introduction portion. Even in this case, the condensed water can be discharged from the gap portion of the introduction portion to the exhaust passage through the communication portion of the introduction portion. Then, the condensed water discharged from the gap portion of the introduction portion to the exhaust passage through the communication portion of the introduction portion flows through the exhaust passage together with the exhaust gas flowing through the exhaust passage, or evaporates due to the heat of the exhaust gas. It is possible to prevent the condensed water from accumulating in the gap between the introduction channel and the introduction flow path forming plate.

In the turbine housing, the introduction portion communication portion may be formed at the lowermost portion of the introduction flow path forming plate.
Since the condensed water generated in the gap portion of the introduction portion flows downward in the vertical direction through the gap portion of the introduction portion due to its own weight, the condensed water generated in the gap portion of the introduction portion tends to collect at the bottom of the gap portion of the introduction portion. At this time, since the introduction portion communication portion is formed at the lowermost portion of the introduction passage forming plate, the condensed water collected at the lowermost portion of the introduction portion gap portion is exhausted from the introduction portion gap portion via the introduction portion communication portion. Easy to be discharged into the passage. Therefore, the condensed water generated in the gap portion of the introduction portion can be efficiently discharged from the gap portion of the introduction portion to the exhaust passage through the communication portion of the introduction portion, and it is possible to prevent the condensed water from accumulating in the gap portion of the introduction portion. It can be made easy.

In the turbine housing, the interior member further has an annular plate forming an inner wall on the closing member side in the scroll flow path, and the gap is formed between the closing member and the annular plate. It is preferable that the communication portion includes an annular gap portion, and the communication portion includes an annular plate communication portion that communicates the annular gap portion and the scroll flow path.

Exhaust gas flows into the annular gap formed between the closing member and the annular plate, and heat exchange is performed between the exhaust gas flowing into the annular gap and the closing member to cool the exhaust gas and exhaust gas. The water vapor contained therein may condense to generate condensed water in the annular voids. Even in this case, the condensed water can be discharged from the annular gap portion to the scroll flow path via the annular plate communication portion. Then, the condensed water discharged from the annular gap portion to the scroll flow path through the annular plate communication portion flows through the scroll flow path together with the exhaust gas flowing through the scroll flow path, or evaporates due to the heat of the exhaust gas. Therefore, in addition to suppressing the accumulation of condensed water in the scroll gap between the housing body and the scroll flow path forming plate, the condensed water is collected in the annular gap between the closing member and the annular plate. Accumulation can also be suppressed.

In the turbine housing, the exterior member includes a bottomed tubular housing main body having a plate-shaped bottom wall and a peripheral wall erected in a cylindrical shape from the outer peripheral portion of the bottom wall, and the housing main body. The interior member includes a scroll flow path forming plate that closes an opening of the peripheral wall, and a scroll flow path forming plate that forms an inner wall on the housing main body side in the scroll flow path, and the blockage in the scroll flow path. It has an annular plate forming an inner wall on the member side, the gap portion includes an annular gap portion formed between the closing member and the annular plate, and the communication portion is with the annular gap portion. It is preferable to include an annular plate communication portion that communicates with the scroll flow path.

Exhaust gas flows into the annular gap formed between the closing member and the annular plate, and heat exchange is performed between the exhaust gas flowing into the annular gap and the closing member to cool the exhaust gas and exhaust gas. The water vapor contained therein may condense to generate condensed water in the annular voids. Even in this case, the condensed water can be discharged from the annular gap portion to the scroll flow path via the annular plate communication portion. Then, the condensed water discharged from the annular gap portion to the scroll flow path via the annular plate communication portion flows through the scroll flow path together with the exhaust gas flowing through the scroll flow path, or evaporates due to the heat of the exhaust gas, so that the closing member It is possible to prevent the condensed water from accumulating in the annular gap between the and the annular plate.

According to the present invention, it is possible to prevent the condensed water from accumulating in the gap between the exterior member and the interior member.

A side sectional view of the turbocharger according to the first embodiment. A side sectional view showing a part of the turbocharger in an enlarged manner. Longitudinal section of the turbocharger. FIG. 5 is an enlarged cross-sectional view showing a part of the turbine housing. FIG. 5 is an enlarged cross-sectional view showing a part of the turbine housing according to the second embodiment. A side sectional view showing a part of a turbocharger in another embodiment in an enlarged manner.

(First Embodiment)
Hereinafter, the first embodiment in which the turbine housing used in the turbocharger is embodied will be described with reference to FIGS. 1 to 4. The turbocharger of this embodiment is mounted on a vehicle. The turbocharger supercharges the intake air to the engine of the vehicle.

As shown in FIG. 1, the housing 11 of the turbocharger 10 includes a bearing housing 20, a turbine housing 30, and a compressor housing 40. The bearing housing 20 and the compressor housing 40 are made of casting. Exhaust gas discharged from the engine E flows inside the turbine housing 30. The intake air guided to the engine E flows inside the compressor housing 40.

The bearing housing 20 rotatably supports the impeller shaft 12. A turbine wheel 13 is connected to one end of the impeller shaft 12 in the direction of the rotation axis. A compressor impeller 14 is connected to the other end of the impeller shaft 12 in the direction of the rotation axis. The turbine housing 30 is connected to one end of the bearing housing 20 in the direction of the rotation axis of the impeller shaft 12. The compressor housing 40 is connected to the other end of the bearing housing 20 in the direction of the rotation axis of the impeller shaft 12.

The bearing housing 20 has a cylindrical main body 21 having an insertion hole 21h through which the impeller shaft 12 is inserted. The main body 21 rotatably supports the impeller shaft 12 inserted through the insertion hole 21h via a radial bearing 15. The axial direction of the main body 21 coincides with the rotation axis direction of the impeller shaft 12.

The main body 21 has a large diameter portion 211 and a small diameter portion 212 having an outer diameter smaller than that of the large diameter portion 211 while being continuous with one end of the impeller shaft 12 in the large diameter portion 211 in the rotation axis direction. .. The main body 21 has a cylindrical protrusion 22 that protrudes from one end surface 21a located in the direction of the rotation axis of the impeller shaft 12 in the small diameter portion 212. The protruding portion 22 has a shape in which the outer diameter gradually decreases as the distance from the small diameter portion 212 in the direction of the rotation axis of the impeller shaft 12 increases. The insertion hole 21h is open to the tip surface 22a of the protrusion 22. An annular convex portion 22b protruding from the tip surface 22a of the protruding portion 22 is formed around the insertion hole 21h in the tip surface 22a of the protruding portion 22.

A housing recess 23 is formed in the large diameter side end surface 21b located on the compressor housing 40 side in the rotation axis direction of the impeller shaft 12 in the large diameter portion 211. The insertion hole 21h is open to the bottom surface of the accommodating recess 23. The hole diameter of the accommodating recess 23 is larger than the hole diameter of the insertion hole 21h. The axis of the accommodating recess 23 coincides with the axis of the insertion hole 21h. A thrust bearing 16 is housed in the housing recess 23. The thrust bearing 16 is housed in the housing recess 23 in a state of being in contact with the bottom surface of the housing recess 23.

The bearing housing 20 has a small diameter side flange portion 24 protruding outward in the radial direction of the impeller shaft 12 from the outer peripheral surface of the small diameter portion 212, and an impeller shaft from an end portion on the outer peripheral surface of the large diameter portion 211 opposite to the small diameter portion 212. It has a large-diameter side flange portion 25 projecting outward in the radial direction of the twelve. The small diameter side flange portion 24 and the large diameter side flange portion 25 are annular, respectively.

The compressor housing 40 has a bottomed cylindrical compressor main body 41. The compressor main body 41 has a substantially disk-shaped bottom wall 41a and a cylindrical peripheral wall 41b erected from the peripheral edge of the bottom wall 41a in the direction of the rotation axis of the impeller shaft 12. One side of the peripheral wall 41b on the opposite side of the bottom wall 41a is open. The compressor housing 40 is connected to the other end of the impeller shaft 12 in the bearing housing 20 in the direction of the rotation axis by attaching the end portion on the opening side of the peripheral wall 41b and the flange portion 25 on the large diameter side by a screw (not shown). .. The opening of the peripheral wall 41b is closed by the end face 21b on the large diameter side of the main body 21 and the end face on the flange portion 25 on the large diameter side opposite to the flange portion 24 on the small diameter side. That is, the opening of the peripheral wall 41b is closed by the end face located at the other end of the impeller shaft 12 in the bearing housing 20 in the direction of the rotation axis.

Further, the compressor housing 40 has a compressor tubular portion 42 protruding from the bottom wall 41a to the side opposite to the peripheral wall 41b. The compressor tubular portion 42 has an intake port 42a. The intake port 42a extends in the direction of the rotation axis of the impeller shaft 12. The axis of the intake port 42a coincides with the rotation axis of the impeller shaft 12.

A compressor impeller chamber 43, a diffuser flow path 44, and a compressor scroll flow path 45 are formed in the compressor housing 40. The compressor impeller chamber 43 communicates with the intake port 42a and houses the compressor impeller 14. The compressor scroll flow path 45 circulates around the outer circumference of the compressor impeller chamber 43 in a spiral shape. The diffuser flow path 44 extends in an annular shape around the compressor impeller chamber 43, and communicates the compressor impeller chamber 43 with the compressor scroll flow path 45.

A cylindrical shroud member 46 is provided in the compressor housing 40. The shroud member 46 has a tubular portion 46a extending along the inner peripheral surface of the compressor tubular portion 42, and an annular portion 46b continuous with the tubular portion 46a and extending annularly along the inner bottom surface of the bottom wall 41a. ing. The compressor impeller chamber 43 is a space surrounded by the tubular portion 46a of the shroud member 46 and the accommodating recess 23 of the bearing housing 20.

The compressor impeller 14 has a shaft insertion hole 14h extending in the direction of the rotation axis of the impeller shaft 12 and into which the impeller shaft 12 can be inserted. The other end of the impeller shaft 12 in the direction of the rotation axis projects into the compressor impeller chamber 43. Then, the compressor impeller 14 is provided with a nut or the like so that the portion of the impeller shaft 12 protruding into the compressor impeller chamber 43 can rotate integrally with the impeller shaft 12 in a state of being inserted into the shaft insertion hole 14h. Is attached to the impeller shaft 12. The end of the compressor impeller 14 on the bearing housing 20 side is supported by the thrust bearing 16 via a seal ring collar, a thrust collar, or the like (not shown). The thrust bearing 16 receives a load in the thrust direction acting on the compressor impeller 14.

The surface 46c of the annular portion 46b of the shroud member 46 facing the bearing housing 20 is a flat surface extending in the radial direction of the impeller shaft 12. The diffuser flow path 44 is a surface 46c of the annular portion 46b and an end surface located at the other end of the bearing housing 20 in the direction of the rotation axis, and the surface 46c of the annular portion 46b and the impeller shaft 12. It is formed between the parts facing each other in the direction of the rotation axis.

An annular compressor scroll member 47 is provided in the compressor housing 40. The compressor scroll member 47 extends around the shroud member 46. The compressor scroll flow path 45 is formed by an outer peripheral surface of the annular portion 46b of the shroud member 46, an inner bottom surface of the bottom wall 41a of the compressor main body 41, and an inner peripheral surface of the compressor scroll member 47. The compressor scroll member 47 and the shroud member 46 may be integrally formed with the compressor housing 40 instead of being separate members from the compressor housing 40.

As shown in FIGS. 2 and 3, the turbine housing 30 is formed of a cast exterior member 30a and a sheet metal interior member 30b housed in the exterior member 30a. The exterior member 30a accommodates the interior member 30b via the gap G.

The exterior member 30a has a bottomed cylindrical housing main body 31 and a closing member 38. The housing main body 31 has a substantially disk-shaped bottom wall 31a and a peripheral wall 31b that is erected in a cylindrical shape in the direction of the rotation axis of the impeller shaft 12 from the outer peripheral portion of the bottom wall 31a. One surface of the peripheral wall 31b on the opposite side of the bottom wall 31a is open.

As shown in FIG. 2, an annular flange portion 31f protruding outward in the radial direction of the impeller shaft 12 is formed at an end portion on the outer peripheral surface of the peripheral wall 31b on the opening side. The end surface 31c of the flange portion 31f on the side opposite to the bottom wall 31a is located closer to the bearing housing 20 than the end surface 31d on the opening side of the peripheral wall 31b. The end surface 31c of the flange portion 31f and the end surface 31d of the peripheral wall 31b have a flat surface shape extending in the radial direction of the impeller shaft 12.

As shown in FIGS. 1 and 2, the closing member 38 closes the opening of the peripheral wall 31b of the housing main body 31. The closing member 38 has a bottomed tubular shape having a substantially disk-shaped bottom wall 38a and a peripheral wall 38b erected in a cylindrical shape from the outer peripheral portion of the bottom wall 38a. A through hole 38h is formed in the central portion of the bottom wall 38a. The direction in which the axial center of the through hole 38h extends coincides with the axial direction of the peripheral wall 38b. Further, the closing member 38 has an annular flange portion 38c extending radially outward of the impeller shaft 12 from an end portion on the outer peripheral surface of the peripheral wall 38b opposite to the bottom wall 38a. The open end of the peripheral wall 38b is a protruding portion 38d of the flange portion 38c that protrudes from the end surface 381 on the side opposite to the bottom wall 38a. Further, the closing member 38 has a cylindrical extending portion 38e extending from the periphery of the through hole 38h on the outer surface of the bottom wall 38a toward the rotation axis direction of the impeller shaft 12. Further, the closing member 38 has an annular protrusion 38f that projects outward in the radial direction of the impeller shaft 12 from an end portion of the outer peripheral surface of the extending portion 38e that is opposite to the bottom wall 38a.

The closing member 38 is connected to the main body 21 by sandwiching the small diameter side flange portion 24 and the protrusion 38f of the main body 21 of the bearing housing 20 by the fastening force of the clamp member 39. The protruding portion 22 of the main body portion 21 is inserted into the through hole 38h of the closing member 38. Then, in a state where the closing member 38 is connected to the main body 21, the closing member 38 is positioned so as to surround the periphery of the protruding portion 22 of the main body 21.

The turbine housing 30 is formed in the turbine housing 30 by attaching the flange portion 31f and the flange portion 38c with screws 17 in a state where the end surface 31c of the flange portion 31f and the end surface 381 of the flange portion 38c of the closing member 38 are in contact with each other. It is connected to one end of the impeller shaft 12 in the direction of the rotation axis.

A sealing member 18 is provided between the end surface 31c of the flange portion 31f and the end surface 381 of the closing member 38. The sealing member 18 seals between the end surface 31c of the flange portion 31f and the end surface 381 of the closing member 38.

The exterior member 30a has a turbine tubular portion 32 that projects from the bottom wall 31a to the side opposite to the peripheral wall 31b. A discharge port 32a is formed in the turbine tubular portion 32. The discharge port 32a extends in the direction of the rotation axis of the impeller shaft 12. The axis of the discharge port 32a coincides with the rotation axis of the impeller shaft 12. The open end surface 32e of the turbine tubular portion 32 has a flat surface shape extending in the radial direction of the impeller shaft 12.

An annular connecting flange 32f projects from the opening-side end of the outer peripheral surface of the turbine tubular portion 32. Further, a downstream exhaust pipe 19 is connected to the discharge port 32a. The downstream exhaust pipe 19 is connected to the turbine tubular portion 32 by connecting the connecting flange 19f of the downstream exhaust pipe 19 and the connecting flange 32f of the turbine tubular portion 32 to each other in a state of being sandwiched by the clamp member 19c. It is connected. The end surface 19e on the turbine tubular portion 32 side of the downstream exhaust pipe 19 is a flat surface extending parallel to the open end surface 32e of the turbine tubular portion 32.

The downstream exhaust pipe 19 connects the turbocharger 10 and the catalyst C1 provided downstream of the turbine housing 30 in the flow direction of the exhaust gas. The catalyst C1 purifies the exhaust gas. The catalyst C1 exhibits an exhaust gas purification ability when the temperature rises above the activation temperature.

A turbine chamber 33, a communication flow path 34, and a turbine scroll flow path 35 are formed in the turbine housing 30. The turbine scroll flow path 35 is a scroll flow path through which the exhaust gas discharged from the engine E flows. The turbine wheel 13 is housed in the turbine chamber 33. The turbine scroll flow path 35 circulates around the outer circumference of the turbine chamber 33 in a spiral shape. Therefore, the turbine scroll flow path 35 is formed so as to surround the turbine chamber 33 and the turbine wheel 13. The turbine scroll flow path 35 is a part of a flow path that guides the exhaust gas that has flowed into the turbine housing 30 to the turbine chamber 33. The communication flow path 34 extends in an annular shape around the turbine chamber 33 and communicates with the turbine scroll flow path 35 and the turbine chamber 33.

The turbocharger 10 includes a plurality of nozzle vanes 50, a first plate 51, and a second plate 52. The plurality of nozzle vanes 50 make the flow path area of the communication flow path 34 variable, and adjust the flow velocity of the exhaust gas guided to the turbine chamber 33. The plurality of nozzle vanes 50 are arranged at intervals from each other in the circumferential direction of the communication flow path 34.

The first plate 51 is arranged inside the peripheral wall 38b of the closing member 38, and extends in an annular shape around the protrusion 22 of the bearing housing 20. The first plate 51 rotatably supports a plurality of nozzle vanes 50 and forms a wall surface on the bearing housing 20 side in the communication flow path 34. The first plate 51 has an annular convex portion 51f protruding inward in the radial direction of the impeller shaft 12 from the inner peripheral surface of the first plate 51. The convex portion 51f faces the protruding portion 22 in the direction of the rotation axis of the impeller shaft 12.

The second plate 52 has a tubular portion 52a extending along the inner peripheral surface of the turbine tubular portion 32, and an annular portion 52b continuous with the tubular portion 52a and extending along the inner bottom surface 31e of the bottom wall 31a. ing. The turbine chamber 33 is a space surrounded by the tubular portion 52a of the second plate 52, the convex portion 51f of the first plate 51, and the tip surface 22a of the protruding portion 22 of the bearing housing 20. The turbine chamber 33 communicates with the discharge port 32a. Exhaust gas that has passed through the turbine chamber 33 is guided to the discharge port 32a.

The annular portion 52b of the second plate 52 is arranged to face the first plate 51 in the direction of the rotation axis of the impeller shaft 12, and cooperates with the first plate 51 to rotatably support the plurality of nozzle vanes 50. The annular portion 52b forms a wall surface on the communication flow path 34 opposite to the bearing housing 20. The distance between the first plate 51 and the annular portion 52b of the second plate 52 in the direction of the rotation axis of the impeller shaft 12 is held by a plurality of columnar spacers 53. The plurality of spacers 53 are arranged at intervals from each other in the circumferential direction of the communication flow path 34. The plurality of nozzle vanes 50 are driven by a link member (not shown).

The turbine wheel 13 has a fitting convex portion 13f that projects toward the insertion hole 21h. A fitting recess 12f into which the fitting convex portion 13f can be fitted is formed on one end surface of the impeller shaft 12 in the direction of the rotation axis. Then, the turbine wheel 13 is attached to the impeller shaft 12 by welding or the like so that the fitting convex portion 13f can rotate integrally with the impeller shaft 12 in a state where the fitting convex portion 13f is fitted into the fitting concave portion 12f of the impeller shaft 12. It is installed. The turbine wheel 13 is rotated by the exhaust gas introduced into the turbine chamber 33, and the impeller shaft 12 is integrally rotated with the rotation of the turbine wheel 13.

An annular leaf spring 55 is attached to the convex portion 22b of the protruding portion 22. The outer peripheral edge of the leaf spring 55 is in contact with the end surface of the convex portion 51f of the first plate 51 on the bearing housing 20 side. The leaf spring 55 urges the first plate 51 toward the side opposite to the bearing housing 20. As a result, the first plate 51, the plurality of spacers 53, and the second plate 52 are supported by the bottom wall 31a in a state of being pressed against the bottom wall 31a of the housing main body 31.

The exterior member 30a has a bulging wall 36 that bulges toward the side opposite to the bearing housing 20 and surrounds the circumference of the turbine tubular portion 32 on the outer peripheral portion of the bottom wall 31a of the housing main body 31. .. The bulging wall 36 has a bulging outer peripheral wall 36a, a bulging inner peripheral wall 36b, and a bulging continuous wall 36c. The bulging outer peripheral wall 36a is continuous with the end portion of the peripheral wall 31b of the housing main body 31 opposite to the opening side and extends in the direction of the rotation axis of the impeller shaft 12. The bulging inner peripheral wall 36b is located inside the bulging outer peripheral wall 36a and is continuous with a portion radially inside the impeller shaft 12 with respect to the bulging wall 36 on the bottom wall 31a. The bulging continuous wall 36c has an arcuately curved shape that is convex toward the side opposite to the bearing housing 20, and the end edge of the bulging outer wall 36a opposite to the bearing housing 20 and the bulging inner peripheral wall 36b. Is connected to the end edge on the opposite side of the bearing housing 20.

The interior member 30b has a scroll flow path forming plate 60 made of sheet metal. The thickness of the scroll flow path forming plate 60 is thinner than the thickness of the first plate 51 and the second plate 52. The scroll flow path forming plate 60 circulates around the outer circumference of the turbine chamber 33 in a spiral shape. The scroll flow path forming plate 60 has an outer peripheral wall 61, an inner peripheral wall 62, a connecting wall 63, and an inner peripheral edge 64.

The outer peripheral wall 61 surrounds the outer periphery of the turbine chamber 33 on the radial outer side of the impeller shaft 12 with respect to the second plate 52, and forms the outer peripheral side inner surface 35a of the turbine scroll flow path 35. The outer peripheral wall 61 extends along the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the inner peripheral surface of the bulging outer peripheral wall 36a. The outer peripheral surface 61a of the outer peripheral wall 61 is separated from the inner peripheral surface 310 of the peripheral wall 31b and the inner peripheral surface of the bulging outer peripheral wall 36a.

The inner peripheral wall 62 is located inside the outer peripheral wall 61 and forms the inner peripheral side inner surface 35b of the turbine scroll flow path 35. The inner peripheral wall 62 extends along the inner peripheral surface of the bulging inner peripheral wall 36b. The outer peripheral surface 62a of the inner peripheral wall 62 is separated from the inner peripheral surface of the bulging inner peripheral wall 36b. The inner peripheral surface of the inner peripheral wall 62 forming the inner peripheral side inner surface 35b of the turbine scroll flow path 35 is located at substantially the same position in the radial direction of the impeller shaft 12 as the outer peripheral edge of the annular portion 52b of the second plate 52.

The connecting wall 63 connects the edge of the outer peripheral wall 61 opposite to the bearing housing 20 and the edge of the inner peripheral wall 62 opposite to the bearing housing 20. The connecting wall 63 extends along the inner peripheral surface of the bulging connecting wall 36c, and has a shape curved in an arc shape that is convex toward the side opposite to the bearing housing 20. The outer peripheral surface 63a of the connecting wall 63 is separated from the inner peripheral surface of the bulging connecting wall 36c.

The inner peripheral edge 64 extends radially inward from the impeller shaft 12 from the edge of the inner peripheral wall 62 on the bearing housing 20 side. The inner peripheral edge 64 extends between the bottom wall 31a of the housing main body 31 and the annular portion 52b of the second plate 52 in the direction of the rotation axis of the impeller shaft 12. The inner peripheral edge 64 is sandwiched between the bottom wall 31a and the annular portion 52b by the urging force of the leaf spring 55. That is, the inner peripheral edge 64 of the scroll flow path forming plate 60 is sandwiched between the turbine housing 30 and the second plate 52.

The turbine housing 30 includes a scroll gap portion 65 formed between the housing main body portion 31 and the scroll flow path forming plate 60. Therefore, the scroll gap portion 65 is a gap portion G formed between the exterior member 30a and the interior member 30b. Therefore, the gap portion G includes the scroll gap portion 65 formed between the housing main body portion 31 and the scroll flow path forming plate 60. The scroll gap portion 65 is a scroll heat insulating layer formed between the housing main body portion 31 and the scroll flow path forming plate 60. The scroll gap portion 65 blocks heat transfer from the scroll flow path forming plate 60 to the housing main body portion 31.

A scroll elastic member 66 is interposed between the end portion of the outer peripheral surface 61a of the outer peripheral wall 61 opposite to the connecting wall 63 and the housing main body portion 31. The scroll elastic member 66 is located in the scroll gap portion 65. The scroll elastic member 66 is an annular wire mesh attached to the outer peripheral surface 61a of the outer peripheral wall 61. The scroll elastic member 66 is arranged in a crushed state between the outer peripheral surface 61a of the outer peripheral wall 61 and the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31. The scroll elastic member 66 is welded to the outer peripheral surface 61a of the outer peripheral wall 61 by, for example, microspot welding. The outer peripheral wall 61 is supported by the housing main body 31 via the scroll elastic member 66.

The scroll flow path forming plate 60 has an annular flange portion 67 protruding outward in the radial direction of the impeller shaft 12 from the edge of the outer peripheral wall 61 opposite to the connecting wall 63. The flange portion 67 extends toward the opening-side end of the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31. There is a gap between the tip of the flange portion 67 in the protruding direction and the inner peripheral surface 310 of the peripheral wall 31b, and the flange portion 67 and the peripheral wall 31b are not in contact with each other.

The scroll flow path forming plate 60 has a scroll communication portion H1. The scroll communication portion H1 is a notch formed from a part of the flange portion 67 of the scroll flow path forming plate 60 to a part of the edge of the outer peripheral wall 61 opposite to the connecting wall 63. The scroll communication portion H1 penetrates the flange portion 67 and the outer peripheral wall 61 in the respective thickness directions. Then, the scroll communication portion H1 communicates the scroll gap portion 65 with the turbine scroll flow path 35.

As shown in FIGS. 3 and 4, the turbocharger 10 is provided to the vehicle so that the rotation axis of the impeller shaft 12 extends in the horizontal direction and the scroll communication portion H1 is located at the lowermost portion 600 of the scroll flow path forming plate 60. It is installed. Therefore, the scroll communication portion H1 is formed at the lowermost portion 600 of the scroll flow path forming plate 60. The scroll communication portion H1 is open to the lowermost portion 610a of the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60, and faces the lowermost portion 310a of the inner peripheral surface 310 of the peripheral wall 31b of the housing main body portion 31. There is. The axis L of the turbine wheel 13 coincides with the rotation axis of the impeller shaft 12. Therefore, the axis L of the turbine wheel 13 extends in the horizontal direction. The scroll communication portion H1 is formed at a portion of the scroll flow path forming plate 60 located vertically below the axis L of the turbine wheel 13 extending in the horizontal direction.

As shown in FIG. 4, in the scroll gap portion 65, the distance between the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60 is the scroll communication portion H1. It has a void reduction portion R that gradually shortens as it approaches. The gap reducing portion R scrolls between the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60 while passing below the scroll communication portion H1. It extends from the communication portion H1 to both sides of the peripheral wall 31b of the housing main body 31 in the circumferential direction.

In the gap reduction portion R, the distance L1 between the lowermost portion 310a of the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the lowermost portion 610a of the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60 is the housing. It is the shortest between the inner peripheral surface 310 of the peripheral wall 31b of the main body 31 and the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60. Then, in the gap reduction portion R, the distance between the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60 is separated from the lowermost portions 310a and 610a. It gradually becomes longer as you do. Therefore, the gap reducing portion R gradually increases as the distance between the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60 approaches the scroll communication portion H1. It's getting shorter.

As shown in FIG. 2, the interior member 30b has an annular plate 70 made of sheet metal. The annular plate 70 is arranged around the first plate 51, and is arranged so as to face most of the connecting wall 63 of the scroll flow path forming plate 60 in the direction of the rotation axis of the impeller shaft 12. The thickness of the annular plate 70 is thinner than the thickness of the first plate 51 and the second plate 52.

The turbine scroll flow path 35 is formed by an outer peripheral wall 61, an inner peripheral wall 62, and a connecting wall 63 in the scroll flow path forming plate 60, and a portion of the annular plate 70 facing the connecting wall 63. Therefore, the scroll flow path forming plate 60 forms the inner wall of the turbine scroll flow path 35 on the housing body 31 side, and the annular plate 70 forms the inner wall of the turbine scroll flow path 35 on the closing member 38 side. Therefore, the interior member 30b forms at least the inner wall of the turbine scroll flow path 35.

The outer peripheral edge 71 of the annular plate 70 extends between the end face 31d of the peripheral wall 31b and the end face 380 of the protrusion 38d. The outer peripheral edge 71 of the annular plate 70 is sandwiched between the end surface 31d of the peripheral wall 31b and the end surface 380 of the protruding portion 38d by the fastening force of the screw 17. That is, the outer peripheral edge 71 of the annular plate 70 is sandwiched between the housing main body 31 and the closing member 38.

The turbine housing 30 includes an annular gap 74 formed between the peripheral wall 38b of the closing member 38 and the annular plate 70. Therefore, the annular gap portion 74 is a gap portion G formed between the exterior member 30a and the interior member 30b. Therefore, the gap portion G includes the annular gap portion 74 formed between the closing member 38 and the annular plate 70. The annular gap portion 74 is a scroll heat insulating layer formed between the closing member 38 and the annular plate 70. The annular gap 74 blocks heat transfer from the annular plate 70 to the closing member 38.

The annular plate 70 has a cylindrical rib 73 that protrudes from the inner peripheral portion 72 of the annular plate 70 in the direction of the rotation axis of the impeller shaft 12 toward the side opposite to the scroll flow path forming plate 60. The rib 73 extends along the outer peripheral edge of the first plate 51. There is a slight gap between the inner peripheral surface of the rib 73 and the outer peripheral edge of the first plate 51, and the rib 73 is in non-contact with the first plate 51.

As shown in FIGS. 1 and 2, the turbocharger 10 includes a cylindrical discharge port forming member 80 made of sheet metal that forms the wall surface of the discharge port 32a. The discharge port forming member 80 is formed from the cylindrical discharge port main body wall 81 forming the wall surface of the discharge port 32a and the end edge of the discharge port main body wall 81 opposite to the turbine chamber 33 to the outside in the radial direction of the impeller shaft 12. It has an annular discharge port outer peripheral edge 82 extending toward the surface.

The end portion 81a on the turbine chamber 33 side of the discharge port main body wall 81 surrounds the end portion of the tubular portion 52a of the second plate 52 opposite to the annular portion 52b. A discharge port elastic member 83 is interposed between the end portion of the outer peripheral surface 81b of the discharge port main body wall 81 on the turbine chamber 33 side and the inner peripheral surface of the turbine tubular portion 32. The discharge port elastic member 83 is an annular wire mesh attached to the outer peripheral surface 81b of the discharge port main body wall 81. The discharge port elastic member 83 is arranged in a crushed state between the outer peripheral surface 81b of the discharge port main body wall 81 and the inner peripheral surface of the turbine tubular portion 32. The discharge port elastic member 83 is welded to the outer peripheral surface 81b of the discharge port main body wall 81 by, for example, microspot welding. The discharge port main body wall 81 is supported by the turbine tubular portion 32 via the discharge port elastic member 83.

The discharge port outer peripheral edge 82 projects from the opening of the turbine tubular portion 32 and extends along the opening end surface 32e of the turbine tubular portion 32. The discharge port outer peripheral edge 82 is sandwiched between the open end surface 32e of the turbine tubular portion 32 and the end surface 19e of the downstream exhaust pipe 19 by the fastening force of the clamp member 19c. That is, the outer peripheral edge 82 of the discharge port is sandwiched between the turbine housing 30 and the downstream exhaust pipe 19.

The turbocharger 10 includes a discharge port air layer 84 formed between the outer peripheral surface 81b of the discharge port main body wall 81 and the inner peripheral surface of the turbine tubular portion 32. The discharge port air layer 84 is a discharge port heat insulating layer formed between the discharge port forming member 80 and the exterior member 30a. The discharge port air layer 84 blocks heat transfer from the discharge port forming member 80 to the turbine tubular portion 32.

As shown in FIG. 3, the exterior member 30a has a cylindrical introduction portion forming portion 37 protruding from the outer peripheral surface of the housing main body portion 31. In FIG. 3, for convenience of explanation, the second plate 52 and the turbine wheel 13 are not shown.

Further, the interior member 30b has a tubular introduction flow path forming plate 90 made of sheet metal that forms an inner wall of the introduction flow path 37a for introducing exhaust gas into the turbine scroll flow path 35. The introduction flow path forming plate 90 has a cylindrical main body 90a whose inner diameter and outer diameter gradually increase from one end to the other end, and an annular shape protruding outward from the other end of the tubular main body 90a. It has a flange portion 90f and a flange portion 90f. One end of the tubular body 90a is one end of the introduction flow path forming plate 90, and the flange 90f is the other end of the introduction flow path forming plate 90.

The inner peripheral surface 370 of the introduction portion forming portion 37 extends along the outer peripheral surface 900 of the tubular main body portion 90a. The introduction flow path forming plate 90 is inserted into the inside of the introduction portion forming portion 37 from the one end side of the cylindrical main body portion 90a. Therefore, the introduction portion forming portion 37 accommodates the introduction flow path forming plate 90. The introduction flow path 37a is formed inside the introduction portion forming portion 37. Therefore, the introduction flow path 37a is formed in the turbine housing 30.

The scroll flow path forming plate 60 has a tubular portion 68 into which the exhaust gas from the introduction flow path 37a is introduced. The tubular portion 68 communicates with the turbine scroll flow path 35. One end of the cylindrical main body 90a of the introduction flow path forming plate 90 is inserted inside the cylindrical portion 68. One end of the tubular main body 90a of the introduction flow path forming plate 90 is surrounded by the cylindrical portion 68. One end of the introduction flow path forming plate 90 is not fixed to the scroll flow path forming plate 60 and is a free end. The introduction flow path 37a and the turbine scroll flow path 35 communicate with each other via the cylindrical portion 68.

The turbine housing 30 includes an introduction portion gap portion 92 formed between the inner peripheral surface 370 of the introduction portion forming portion 37 and the outer peripheral surface 900 of the tubular main body portion 90a of the introduction flow path forming plate 90. Therefore, the introduction portion gap portion 92 is a gap portion G formed between the exterior member 30a and the interior member 30b. Therefore, the gap portion G includes the introduction portion gap portion 92 formed between the introduction portion forming portion 37 and the introduction flow path forming plate 90. The introduction portion gap portion 92 is an introduction portion heat insulating layer formed between the introduction passage forming plate 90 and the introduction portion forming portion 37. The introduction portion gap 92 blocks heat transfer from the introduction flow path forming plate 90 to the introduction portion forming portion 37.

An introduction portion elastic member 93 is interposed between a portion of the outer peripheral surface 900 of the tubular main body portion 90a of the introduction flow path forming plate 90 near one end and the inner peripheral surface 370 of the introduction portion forming portion 37. The introduction portion elastic member 93 is an annular wire mesh attached to the outer peripheral surface 900 of the tubular main body portion 90a of the introduction flow path forming plate 90. The introduction portion elastic member 93 is arranged in a crushed state between the outer peripheral surface 900 of the tubular main body portion 90a of the introduction flow path forming plate 90 and the inner peripheral surface 370 of the introduction portion forming portion 37. The introduction portion elastic member 93 is welded to the outer peripheral surface 900 of the tubular main body portion 90a of the introduction flow path forming plate 90 by, for example, microspot welding. The introduction flow path forming plate 90 is supported by the introduction portion forming portion 37 via the introduction portion elastic member 93.

The end of the introduction portion forming portion 37 on the side opposite to the housing main body portion 31 is an annular flange portion 37f. The opening of the introduction portion forming portion 37 on the side opposite to the housing main body portion 31 is continuous with the end surface 371 of the flange portion 37f. Further, the opening of the introduction portion forming portion 37 on the side opposite to the housing main body portion 31 has a stepped surface 372 continuous with the end surface 371 of the flange portion 37f.

The flange portion 90f of the introduction flow path forming plate 90 extends along the stepped surface 372 of the introduction portion forming portion 37. The flange portion 90f is sandwiched between the end surface 94e of the upstream exhaust pipe 94 connected to the introduction portion forming portion 37 and the stepped surface 372 of the introduction portion forming portion 37. Specifically, the flange portion 90f is formed by the fastening force of a screw (not shown) for fastening the upstream exhaust pipe 94 and the flange portion 90f to the end surface 94e of the upstream exhaust pipe 94 and the stepped surface 372 of the introduction portion forming portion 37. It is sandwiched between. Therefore, the other end of the introduction flow path forming plate 90 is a fixed end.

In the present embodiment, the turbine scroll flow path 35 is formed by the scroll flow path forming plate 60 and the annular plate 70 constituting the interior member 30b and the portion of the housing main body 31 of the exterior member 30a that accommodates the scroll flow path forming plate 60. The spiral scroll portion S forming the above is configured. Further, in the present embodiment, the introduction passage forming plate 90 constituting the interior member 30b and the introduction portion forming portion 37 of the exterior member 30a constitute the introduction portion I forming the introduction passage 37a. Therefore, the scroll portion S and the introduction portion I are formed by the exterior member 30a and the interior member 30b housed in the exterior member 30a.

The upstream exhaust pipe 94 introduces the exhaust gas discharged from the engine E into the introduction flow path 37a. The exhaust gas introduced into the introduction flow path 37a passes through the inside of the tubular portion 68, the turbine scroll flow path 35, the communication flow path 34, the turbine chamber 33, the discharge port 32a, and the inside of the downstream exhaust pipe 19. Flows to the catalyst C1. Therefore, the inside of the upstream exhaust pipe 94, the introduction flow path 37a, the inside of the tubular portion 68, the turbine scroll flow path 35, the communication flow path 34, the turbine chamber 33, the discharge port 32a, and the inside of the downstream exhaust pipe 19 , Consists of an exhaust passage 95 through which the exhaust gas discharged from the engine E flows. Therefore, the turbine scroll flow path 35 and the introduction flow path 37a are a part of the exhaust passage 95. The scroll communication portion H1 is a communication portion H that communicates the scroll gap portion 65, which is the gap portion G, with the turbine scroll flow path 35, which is a part of the exhaust passage 95. Therefore, the interior member 30b has a communication portion H that communicates the gap portion G and the exhaust passage 95. The communication unit H includes the scroll communication unit H1. The communication portion H is formed at a portion of the interior member 30b located vertically below the axis L of the turbine wheel 13 extending in the horizontal direction.

When the exhaust gas is introduced into the turbine chamber 33, the turbine wheel 13 is rotated by the exhaust gas introduced into the turbine chamber 33. Then, as the turbine wheel 13 rotates, the compressor impeller 14 rotates integrally with the turbine wheel 13 via the impeller shaft 12. When the compressor impeller 14 rotates, the intake air introduced into the compressor impeller chamber 43 through the intake port 42a is compressed by the rotation of the compressor impeller 14 and decelerated as it passes through the diffuser flow path 44, and the speed of the intake air is reduced. Energy is converted to pressure energy. Then, the high-pressure intake air is discharged to the compressor scroll flow path 45 and supplied to the engine E. By supercharging the intake air to the engine E by such a turbocharger 10, the intake efficiency of the engine E is increased and the performance of the engine E is improved.

Next, the operation of the first embodiment will be described.
Since the introduction flow path forming plate 90, the scroll flow path forming plate 60, the annular plate 70, and the discharge port forming member 80 suppress the heat transfer of the exhaust gas to the exterior member 30a, the exhaust gas flows in the turbine housing 30. It is difficult for heat to be taken in between, and it is difficult for the temperature to drop. As a result, the time until the temperature of the catalyst C1 rises above the activation temperature is shortened. Therefore, for example, under operating conditions that require early warm-up of the catalyst C1 such as during a cold start of the engine E, the temperature of the catalyst C1 tends to rise above the activation temperature at an early stage.

By the way, the exhaust gas discharged from the engine E contains water vapor. The exhaust gas discharged from the engine E flows into the introduction flow path 37a from the upstream exhaust pipe 94, and is introduced into the turbine scroll flow path 35 from the introduction flow path 37a via the tubular portion 68. Here, the scroll flow path forming plate 60 is warmed by the heat of the exhaust gas, but since the scroll gap portion 65 is formed between the housing main body 31 and the scroll flow path forming plate 60, the scroll flow path forming plate 60 is formed. It is difficult to transfer heat from the 60 to the housing main body 31. Therefore, there is a temperature difference between the housing main body 31 and the scroll flow path forming plate 60, and the temperature of the housing main body 31 is lower than that of the scroll flow path forming plate 60.

At this time, for example, when the exhaust gas flows into the scroll gap portion 65 between the housing main body 31 and the scroll flow path forming plate 60, heat exchange occurs between the exhaust gas flowing into the scroll gap 65 and the housing main body 31. By doing so, the exhaust gas may be cooled, and the water vapor contained in the exhaust gas may be condensed to generate condensed water W in the scroll gap 65. The condensed water W generated in this way travels by its own weight along the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60, and moves the scroll gap portion 65 downward in the vertical direction. It will flow. Then, the condensed water W accumulated at the lowermost portion of the scroll gap portion 65 is discharged to the turbine scroll flow path 35 via the scroll communication portion H1. The condensed water W discharged from the scroll gap portion 65 to the turbine scroll flow path 35 via the scroll communication portion H1 flows through the turbine scroll flow path 35 together with the exhaust gas flowing through the turbine scroll flow path 35, or evaporates due to the heat of the exhaust gas. Therefore, it is suppressed that the condensed water W is accumulated in the scroll gap 65.

In the first embodiment, the following effects can be obtained.
(1-1) Even if the water vapor contained in the exhaust gas condenses and the condensed water W is generated in the scroll gap 65, the condensed water W is passed from the scroll gap 65 through the scroll communication portion H1 to the turbine scroll flow path. It can be discharged to 35. Then, the condensed water W discharged from the scroll gap portion 65 to the turbine scroll flow path 35 via the scroll communication portion H1 flows through the turbine scroll flow path 35 together with the exhaust gas flowing through the turbine scroll flow path 35, or is caused by the heat of the exhaust gas. It evaporates. Therefore, it is possible to prevent the condensed water W from accumulating in the scroll gap portion 65 between the exterior member and the scroll flow path forming plate 60.

(1-2) The scroll communication portion H1 is formed at a portion of the scroll flow path forming plate 60 located vertically below the axis L of the turbine wheel 13 extending in the horizontal direction. As a result, the condensed water W flowing downward in the vertical direction through the scroll gap 65 due to its own weight is easily discharged from the scroll gap 65 to the turbine scroll flow path 35 via the scroll communication portion H1. Therefore, the condensed water W generated in the scroll gap portion 65 can be efficiently discharged from the scroll gap portion 65 to the turbine scroll flow path 35 via the scroll communication portion H1, and the condensed water W is accumulated in the scroll gap portion 65. It can be easily suppressed from being stowed.

(1-3) Since the condensed water W generated in the scroll gap 65 flows downward in the vertical direction through the scroll gap 65 due to its own weight, the condensed water W generated in the scroll gap 65 is the scroll gap 65. Easy to collect at the bottom. At this time, since the scroll communication portion H1 is formed at the lowermost portion of the scroll flow path forming plate 60, the condensed water W collected at the lowermost portion of the scroll gap portion 65 flows from the scroll gap portion 65 through the scroll communication portion H1. It is easy to be discharged to the turbine scroll flow path 35. Therefore, the condensed water W generated in the scroll gap portion 65 can be efficiently discharged from the scroll gap portion 65 to the turbine scroll flow path 35 via the scroll communication portion H1, and the condensed water W is accumulated in the scroll gap portion 65. It can be easily suppressed from being stowed.

(1-4) In the scroll gap portion 65, the distance between the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60 approaches the scroll communication portion H1. It has a void reduction portion R that gradually shortens as it increases. According to this, the volume of the portion vertically lower than the scroll communication portion H1 in the scroll gap portion 65 is smaller than that in the configuration in which the scroll gap portion 65 does not have the gap reduction portion R. Therefore, the condensed water collected at the lowermost portion of the scroll gap portion 65 is more likely to be discharged from the scroll gap portion 65 to the turbine scroll flow path 35 via the scroll communication portion H1. Therefore, the condensed water W generated in the scroll gap 65 can be more efficiently discharged from the scroll gap 65 to the turbine scroll flow path 35 via the scroll communication portion H1, and the condensed water W is accumulated in the scroll gap 65. It is possible to further suppress the situation.

(1-5) Generally, since the exterior member 30a of the turbine housing 30 needs to secure rigidity, it is formed to be thick by casting, so that it has a large mass and a large heat capacity. Therefore, in the turbine housing 30 of the present embodiment, the interior member 30b made of sheet metal is housed in the exterior member 30a, and the interior member 30b suppresses the transfer of heat of the exhaust gas to the exterior member 30a. According to this, it is suppressed that the temperature of the exhaust gas drops while the exhaust gas flows in the turbine housing 30, so that the time until the temperature of the catalyst C1 rises above the activation temperature is shortened. Can be done. Therefore, for example, the temperature of the catalyst C1 can be raised to the activation temperature or higher at an early stage under operating conditions that require early warming up of the catalyst C1 such as during a cold start of the engine E.

(Second Embodiment)
Hereinafter, a second embodiment in which the turbine housing is embodied will be described with reference to FIG. In the embodiments described below, the duplicated description will be omitted or simplified by adding the same reference numerals to the same configurations as those of the first embodiment already described.

As shown in FIG. 5, the turbocharger 10 is arranged so that the rotation axis of the impeller shaft 12 extends in the horizontal direction and the tubular main body 90a of the introduction flow path forming plate 90 opens downward in the vertical direction. It is mounted on the vehicle. At this time, the axial direction of the cylindrical main body 90a coincides with the vertical direction. Therefore, the flange portion 90f of the introduction flow path forming plate 90 is located at the lowermost portion of the introduction flow path forming plate 90.

An introduction portion communication portion H2 is formed on the flange portion 90f of the introduction flow path forming plate 90. Therefore, the introduction portion communication portion H2 is formed at the lowermost portion of the introduction flow path forming plate 90. The introduction portion communication portion H2 is formed at a portion of the introduction flow path forming plate 90 located vertically below the axis L of the turbine wheel 13 extending in the horizontal direction. The introduction portion communication portion H2 is a notch formed in a part of the flange portion 90f of the introduction flow path forming plate 90. The introduction portion communication portion H2 penetrates in the thickness direction of the flange portion 90f. The introduction portion communication portion H2 communicates the introduction portion gap portion 92 with the inside of the upstream exhaust pipe 94 which is a part of the exhaust passage 95. Therefore, the introduction portion communication portion H2 is a communication portion H that communicates the introduction portion gap portion 92, which is the gap portion G, with the inside of the upstream exhaust pipe 94, which is a part of the exhaust passage 95. Therefore, the interior member 30b has a communication portion H that communicates the gap portion G and the exhaust passage 95. The communication portion H includes an introduction portion communication portion H2 that communicates the introduction portion gap portion 92 and the upstream exhaust pipe 94.

Next, the operation of the second embodiment will be described.
Exhaust gas flows into the introduction portion void 92, and heat is exchanged between the exhaust gas flowing into the introduction gap 92 and the introduction portion forming portion 37, so that the exhaust gas is cooled and contained in the exhaust gas. Condensed water W may be generated in the gap portion 92 of the introduction portion by condensing the existing water vapor. The condensed water W generated in this way flows downward in the vertical direction through the introduction portion gap portion 92 along the inner peripheral surface 370 of the introduction portion forming portion 37 and the outer peripheral surface 900 of the tubular main body portion 90a due to its own weight. Then, the condensed water W that has flowed to the lowermost part of the introduction portion gap 92 is discharged to the inside of the upstream exhaust pipe 94 via the introduction portion communication portion H2 as shown by an arrow A1. The condensed water W discharged from the introduction portion gap 92 to the inside of the upstream exhaust pipe 94 via the introduction portion communication portion H2 flows inside the upstream exhaust pipe 94 together with the exhaust gas flowing inside the upstream exhaust pipe 94. Or, because it evaporates due to the heat of the exhaust gas, it is suppressed that the condensed water W is accumulated in the gap portion 92 of the introduction portion.

In the second embodiment, the following effects can be obtained.
(2-1) Even if the water vapor contained in the exhaust gas condenses and the condensed water W is generated in the introduction portion gap 92, the condensed water W is upstream from the introduction portion void 92 via the introduction portion communication portion H2. It can be discharged to the inside of the side exhaust pipe 94. Then, the condensed water W discharged from the introduction portion gap portion 92 to the inside of the upstream side exhaust pipe 94 via the introduction portion communication portion H2 is inside the upstream side exhaust pipe 94 together with the exhaust gas flowing inside the upstream side exhaust pipe 94. Or evaporates due to the heat of the exhaust gas. Therefore, it is possible to prevent the condensed water W from accumulating in the introduction portion gap 92 between the introduction portion forming portion 37 and the introduction flow path forming plate 90.

(2-2) The introduction portion communication portion H2 is formed at a portion of the introduction flow path forming plate 90 located vertically below the axis L of the turbine wheel 13 extending in the horizontal direction. As a result, the condensed water W that flows downward in the vertical direction through the introduction portion gap 92 due to its own weight is easily discharged from the introduction portion gap 92 to the inside of the upstream exhaust pipe 94 via the introduction portion communication portion H2. Therefore, the condensed water W generated in the introduction portion gap 92 can be efficiently discharged from the introduction portion gap 92 to the upstream exhaust pipe 94 via the introduction portion communication portion H2, and the condensed water can be efficiently discharged to the introduction portion gap 92. It is possible to easily suppress the accumulation of W.

(2-3) Since the condensed water W generated in the introduction portion gap 92 flows downward in the vertical direction through the introduction portion gap 92 due to its own weight, the condensed water W generated in the introduction portion gap 92 is the introduction portion. It tends to collect at the bottom of the gap 92. At this time, since the introduction portion communication portion H2 is formed in the flange portion 90f located at the lowermost portion of the introduction passage forming plate 90, the condensed water W collected at the lowermost portion of the introduction portion gap portion 92 is the introduction portion gap. It is easy to be discharged from the section 92 to the upstream exhaust pipe 94 via the introduction section communication section H2. Therefore, the condensed water W generated in the introduction portion gap 92 can be efficiently discharged from the introduction portion gap 92 to the upstream exhaust pipe 94 via the introduction portion communication portion H2, and the condensed water can be efficiently discharged to the introduction portion gap 92. It is possible to easily suppress the accumulation of W.

Each of the above embodiments can be modified and implemented as follows. The above embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

○ As shown in FIG. 6, the annular plate 70 may have a configuration having an annular plate communication portion H3 that communicates the annular gap portion 74 and the turbine scroll flow path 35. The annular plate communication portion H3 is formed in the annular plate 70 at a portion radially inside the outer peripheral edge 71 sandwiched between the end surface 31d of the peripheral wall 31b of the housing main body 31 and the end surface 380 of the protruding portion 38d. The annular plate communication portion H3 is a through hole that penetrates the annular plate 70 in the thickness direction. The annular plate communication portion H3 faces the scroll communication portion H1 in the axial direction of the turbine wheel 13. Therefore, the annular plate communication portion H3 is formed at a portion of the annular plate 70 located vertically below the axis L of the turbine wheel 13 extending in the horizontal direction. The annular plate communication portion H3 is a communication portion H that communicates the annular gap portion 74, which is the gap portion G, with the turbine scroll flow path 35, which is a part of the exhaust passage 95. Therefore, the communication portion H includes an annular plate communication portion H3 that communicates the annular gap portion 74 and the turbine scroll flow path 35.

Exhaust gas flows into the annular gap 74 formed between the closing member 38 and the annular plate 70, and heat exchange is performed between the exhaust gas flowing into the annular gap 74 and the closing member 38, so that the exhaust gas is discharged. When cooled, the water vapor contained in the exhaust gas may condense to generate condensed water W in the annular void 74. Even in this case, the condensed water W can be discharged from the annular gap portion 74 to the turbine scroll flow path 35 via the annular plate communication portion H3. Then, the condensed water W discharged from the annular gap portion 74 to the turbine scroll flow path 35 via the annular plate communication portion H3 flows through the turbine scroll flow path 35 together with the exhaust gas flowing through the turbine scroll flow path 35, or the heat of the exhaust gas. Evaporates due to. Therefore, in addition to suppressing the accumulation of condensed water W in the scroll gap portion 65 between the housing main body portion 31 and the scroll flow path forming plate 60, the annular shape between the closing member 38 and the annular plate 70 is formed. It is also possible to prevent the condensed water W from accumulating in the gap 74.

○ In each of the above embodiments, the exterior member 30a does not have to be made of casting, and the interior member 30b does not have to be made of sheet metal. In short, the material of each of the exterior member 30a and the interior member 30b may be appropriately changed as long as the turbine housing 30 has a structure having a double structure including the exterior member 30a and the interior member 30b.

○ In the first embodiment and the embodiment shown in FIG. 6, the scroll communication portion H1 does not have to be a notch, and may be, for example, a through hole.
○ In the second embodiment, the introduction portion communication portion H2 does not have to be a notch, and may be, for example, a through hole.

○ In the embodiment shown in FIG. 6, the turbine housing 30 may have a configuration in which the scroll communication portion H1 is not formed on the scroll flow path forming plate 60. Even in this case, the condensed water W can be discharged from the annular gap portion 74 to the turbine scroll flow path 35 via the annular plate communication portion H3. Then, the condensed water W discharged from the annular gap portion 74 to the turbine scroll flow path 35 via the annular plate communication portion H3 flows through the turbine scroll flow path 35 together with the exhaust gas flowing through the turbine scroll flow path 35, or the heat of the exhaust gas. Evaporates due to. Therefore, it is possible to prevent the condensed water W from accumulating in the annular gap 74 between the closing member 38 and the annular plate 70.

○ In the first embodiment, the scroll gap portion 65 may have a configuration that does not have the gap reduction portion R. For example, the distance between the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60 is always constant in the circumferential direction of the peripheral wall 31b of the housing main body 31. There may be. Further, the distance between the inner peripheral surface 310 of the peripheral wall 31b of the housing main body 31 and the outer peripheral surface 61a of the outer peripheral wall 61 of the scroll flow path forming plate 60 may gradually increase as it approaches the scroll communication portion H1.

-In the first embodiment, the scroll communication portion H1 may not be formed at the lowermost portion of the scroll flow path forming plate 60. Even in this case, for example, the scroll communication portion H1 is preferably formed at a portion of the scroll flow path forming plate 60 located vertically below the axis L of the turbine wheel 13 extending in the horizontal direction. ..

○ In the first embodiment, the scroll communication portion H1 may be formed, for example, at a portion of the scroll flow path forming plate 60 located vertically above the axis L of the turbine wheel 13 extending in the horizontal direction. In short, it suffices if the condensed water W generated in the scroll gap portion 65 can be discharged to the turbine scroll flow path 35 via the scroll communication portion H1, and the formation position of the scroll communication portion H1 with respect to the scroll flow path forming plate 60 is particularly high. It is not limited.

○ In the second embodiment, the introduction portion communication portion H2 may not be formed on the flange portion 90f located at the lowermost portion of the introduction flow path forming plate 90, for example, the tubular shape of the introduction flow path forming plate 90. The introduction portion communication portion H2 may be formed so as to penetrate the main body portion 90a in the thickness direction. In this case, the introduction portion communication portion H2 communicates the introduction portion gap portion 92 with the introduction passage 37a which is a part of the exhaust passage 95. Then, the condensed water W generated in the introduction portion gap 92 is discharged to the introduction flow path 37a via the introduction portion communication portion H2.

13 ... Turbine wheel, 30 ... Turbine housing, 30a ... Exterior member, 30b ... Interior member, 31 ... Housing body, 31a ... Bottom wall, 31b ... Circumferential wall, 35 ... Turbine scroll flow path as scroll flow path, 37a ... Introduction Flow path, 38 ... Closing member, 60 ... Scroll flow path forming plate, 61a ... Outer surface, 65 ... Scroll gap, 70 ... Circular plate, 74 ... Circular gap, 90 ... Introduction flow path forming plate, 92 ... Introduction Void part, 95 ... Exhaust passage, 310 ... Inner peripheral surface, E ... Engine, G ... Void part, H ... Communication part, H1 ... Scroll communication part, H2 ... Introduction part communication part, H3 ... Circular plate communication part, R ... Void reduction part, W ... Condensed water.

Claims (9)

An interior member that is part of the exhaust passage through which the exhaust gas discharged from the engine flows and at least forms the inner wall of the spiral scroll passage that is formed so as to surround the turbine wheel.
A turbine housing formed by an exterior member that accommodates the interior member via a gap portion.
The interior member is a turbine housing characterized by having a communication portion for communicating the gap portion and the exhaust passage. The turbine housing according to claim 1, wherein the communication portion is formed in a portion of the interior member located vertically below the axis of the turbine wheel extending in the horizontal direction. The exterior member is
A bottomed tubular housing main body having a plate-shaped bottom wall and a peripheral wall erected in a cylindrical shape from the outer peripheral portion of the bottom wall.
It has a closing member that closes the opening of the peripheral wall of the housing main body, and has.
The interior member
It has a scroll flow path forming plate that forms an inner wall on the housing main body side in the scroll flow path.
The gap portion includes a scroll gap portion formed between the housing main body portion and the scroll flow path forming plate.
The turbine housing according to claim 1 or 2, wherein the communication portion includes a scroll communication portion that communicates the scroll gap portion with the scroll flow path. The turbine housing according to claim 3, wherein the scroll communication portion is formed at the lowermost portion of the scroll flow path forming plate. The scroll gap portion has a gap reduction portion in which the distance between the inner peripheral surface of the housing main body portion and the outer peripheral surface of the scroll flow path forming plate gradually becomes shorter as the distance between the scroll passage forming plate approaches the scroll communication portion. The turbine housing according to claim 4, wherein the turbine housing is provided. The interior member has a cylindrical introduction flow path forming plate that is a part of the exhaust passage and forms an inner wall of the introduction flow path for introducing the exhaust gas into the scroll flow path.
The exterior member has a cylindrical introduction portion forming portion for accommodating the introduction flow path forming plate.
The gap portion includes an introduction portion gap portion formed between the introduction portion forming portion and the introduction flow path forming plate.
The turbine housing according to claim 2, wherein the communication portion includes an introduction portion communication portion that communicates the introduction portion gap portion with the exhaust passage. The turbine housing according to claim 6, wherein the introduction portion communication portion is formed at the lowermost portion of the introduction flow path forming plate. The interior member further comprises an annular plate forming an inner wall on the closing member side of the scroll flow path.
The gap includes an annular gap formed between the closing member and the annular plate.
The turbine housing according to any one of claims 3 to 5, wherein the communication portion includes an annular plate communication portion that communicates the annular gap portion and the scroll flow path. The exterior member is
A bottomed tubular housing main body having a plate-shaped bottom wall and a peripheral wall erected in a cylindrical shape from the outer peripheral portion of the bottom wall.
It has a closing member that closes the opening of the peripheral wall of the housing main body, and has.
The interior member
A scroll flow path forming plate forming an inner wall on the housing body side in the scroll flow path, and a scroll flow path forming plate.
It has an annular plate that forms an inner wall on the closing member side in the scroll flow path.
The gap includes an annular gap formed between the closing member and the annular plate.
The turbine housing according to claim 1 or 2, wherein the communication portion includes an annular plate communication portion that communicates the annular gap portion with the scroll flow path.

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