JP2013253496A - Turbine housing and turbocharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turbine housing which can reduce pressure loss of exhaust gas in a closed state of a wastegate valve, and to provide a turbocharger.SOLUTION: A turbine housing includes: a main passage 23 in which a turbine is housed; a wastegate passage 30 bypassing the main passage 23; and an outlet part 25 having a recess 26 with a bottom surface 27 to which an outlet 24 of the main passage 23 and an outlet 31 of the wastegate passage 30 are opened. A partition wall 38 is formed to the outlet part 25 to partition the recess 26 into a first chamber 36 provided with the outlet 24 of the main passage 23 and a second chamber 37 provided with the outlet 31 of the wastegate passage 30. A communication hole 40 is formed to the partition wall 38 to connect the first chamber 36 with the second chamber 37.

Description

The technology of the present disclosure relates to a turbine housing including a waste gate passage, and a turbocharger including the turbine housing.

  Conventionally, as disclosed in Patent Document 1, for example, a turbo housing in which a turbine housing includes a main passage that is an exhaust passage having a housing portion in which a turbine wheel is housed, and a waste gate passage that is an exhaust passage that bypasses the housing portion. The charger is known. Such a turbocharger includes a waste gate valve that opens and closes a waste gate passage. The waste gate valve opens the waste gate passage when the exhaust pressure rises above a preset pressure, and bypasses a part of the exhaust gas. Thereby, excessive rotation of the turbine is suppressed, and deformation of the turbine, excessive increase in supercharging pressure, and the like are suppressed. Further, the turbine housing disclosed in Patent Document 1 has a recess in which the outlet of the main passage and the outlet of the waste gate passage open on the bottom surface. Exhaust gas introduced into the turbocharger is exhausted through this recess regardless of whether the wastegate valve is opened or closed.

Japanese National Patent Publication No. 11-506508

  By the way, when the waste gate valve is in the closed state, an exhaust gas jet is formed in the recess by the exhaust gas ejected from the outlet of the main passage. Since such a jet has a property of drawing fluid around the jet, a swirl of exhaust gas is formed near the exit of the waste gate passage. Therefore, when passing through this recess, the exhaust gas has a pressure loss due to the vortex. Since such a pressure loss causes a reduction in efficiency of the turbocharger, in order to improve fuel efficiency and engine output, it is desired to reduce the pressure loss due to the vortex.

  An object of the technology of the present disclosure is to provide a turbine housing and a turbocharger that can reduce pressure loss of exhaust gas when a waste gate valve is in a closed state.

  One aspect of the turbine housing according to the present disclosure includes a main passage in which an inlet portion and an outlet portion are connected to accommodate a turbine wheel, and a waste gate that bypasses the turbine wheel by connecting the inlet portion and the outlet portion. A passageway, and the outlet portion communicates the first chamber and the second chamber formed in the partition wall, the partition wall partitioning the flow path of the outlet portion into a first chamber and a second chamber. The outlet of the main passage opens into the first chamber, and the outlet of the waste gate passage opens into the second chamber.

  According to one aspect of the turbine housing in the present disclosure, the flow path of the outlet portion is partitioned into the first chamber and the second chamber by the partition wall, and the first chamber and the second chamber are formed in the partition wall. It communicates through the communication hole. Therefore, compared with the turbine housing in which the partition wall is omitted, the communication area between the first chamber and the second chamber is reduced, and the exhaust gas in the second chamber is reduced by the amount corresponding to the reduction in the communication area. It becomes difficult to be drawn into the jet of exhaust gas formed on the surface. As a result, the vortex formed near the outlet of the waste gate passage, that is, in the second chamber is weakened, and the pressure loss of the exhaust gas due to the vortex is reduced.

  In another aspect of the turbine housing according to the present disclosure, the outlet portion includes an outlet of the main passage and an outlet of the waste gate passage formed on a bottom surface of a recess formed on an end surface of an outlet flange, and a waste gate on the bottom surface. A valve is provided, and the flow path at the outlet is the recess.

  As in another aspect of the turbine housing in the present disclosure, a recess formed in the outlet flange of the outlet portion can be used as a flow path of the outlet portion, and a waste gate valve can be disposed in the concave portion. Is possible.

In another aspect of the turbine housing according to the present disclosure, the partition wall is formed to follow the shape of the outlet of the main passage in a plan view facing the bottom surface.
According to another aspect of the turbine housing in the present disclosure, the flow passage cross-sectional area related to the exhaust gas flowing through the main passage is abrupt as compared with the case where the partition wall is formed so as not to follow the shape of the outlet of the main passage. Since the change is suppressed, the pressure loss generated in the exhaust gas is further reduced.

In another aspect of the turbine housing according to the present disclosure, the partition wall is connected to a bottom surface of the recess and a side surface of the recess.
According to the other aspect of the turbine housing in the present disclosure, the mechanical strength of the partition wall is increased as compared with the case where the partition wall is connected only to the bottom surface.

In another aspect of the turbine housing according to the present disclosure, the number of the communication holes is one.
In another aspect of the turbine housing according to the present disclosure, the exhaust gas is circulated between the first chamber and the second chamber through the same communication hole, so that the total opening area of the communication holes is equal. Below, the flow of exhaust gas between the first chamber and the second chamber is suppressed compared to the case where a plurality of communication holes are formed in the partition wall along the flow direction of the exhaust gas in the first chamber. . As a result, the vortex formed in the second chamber is weakened, so that the pressure loss generated in the exhaust gas is reduced.

  One aspect of the turbocharger according to the present disclosure includes a main passage in which a turbine wheel is accommodated by connecting an inlet portion and an outlet portion, and a waste gate that bypasses the turbine wheel by connecting the inlet portion and the outlet portion. A turbine housing provided with a passage, wherein the outlet portion is formed in the partition wall and partitions the first chamber and the second chamber into a partition wall that partitions the flow path of the outlet portion into a first chamber and a second chamber. A communication hole that communicates with the chamber, the outlet of the main passage opens into the first chamber, and the outlet of the waste gate passage opens into the second chamber.

  According to one aspect of the turbocharger in the present disclosure, the flow path of the outlet portion is partitioned into the first chamber and the second chamber by the partition wall, and the first chamber and the second chamber are formed in the partition wall. It communicates through the communication hole. Therefore, compared with the turbine housing in which the partition wall is omitted, the communication area between the first chamber and the second chamber is reduced, and the exhaust gas in the second chamber is reduced by the amount corresponding to the reduction in the communication area. It becomes difficult to be drawn into the jet of exhaust gas formed on the surface. As a result, the vortex formed near the outlet of the waste gate passage, that is, in the second chamber is weakened, and the pressure loss of the exhaust gas due to the vortex is reduced.

The perspective view which shows the perspective structure of the turbocharger in the technique of this indication. In the technique of this indication, it is a figure which shows an example of the simulation result regarding the pressure loss of exhaust gas, Comprising: (a) The figure which shows the simulation result of a comparative example, (b) The figure which shows the simulation result of an Example. In the technique of this indication, the graph which compared the pressure loss of the exhaust gas calculated by simulation. It is a top view which shows the planar structure of the turbocharger in the technique of this indication, Comprising: The figure which shows the state by which the exhaust pipe was connected to the exit part. In the technique of this indication, the graph which showed an example of the result of the simulation regarding the pressure loss of exhaust gas.

Hereinafter, an embodiment in which a turbocharger according to the technology of the present disclosure is embodied will be described with reference to FIGS.
As shown in FIG. 1, the turbocharger 10 includes a compressor unit 11 and a turbine unit 12. The exhaust gas from the engine enters the turbine housing 20 of the turbine part 12 from the inlet part 21. Exhaust gas entering the inlet portion 21 flows through a spiral passage formed in the scroll portion 22 through a main passage 23 having a housing portion in which the turbine wheel is housed. The outlet 24 of the main passage 23 is open to a bottom surface 27 of a recess 26 formed on the outlet flange surface of the outlet portion 25. Exhaust gas flowing through the main passage 23 is discharged through the concave portion 26 to an exhaust pipe connected to the outlet portion 25.

  A wastegate passage 30 that bypasses the main passage 23 is formed in the turbine housing 20. The waste gate passage 30 has an inlet in the inlet portion 21 and an outlet 31 in the bottom surface 27 of the recess 26. That is, the turbine housing has a main passage 23 in which the turbine wheel is accommodated by connecting the inlet portion 21 and the outlet portion 25, and a waste gate passage that bypasses the turbine wheel by connecting the inlet portion 21 and the outlet portion 25. 30 are arranged in parallel to the inlet portion 21 and the outlet portion 25.

  A waste gate valve 32 that opens and closes the waste gate passage 30 is disposed at the outlet 31 of the waste gate passage 30. The waste gate valve 32 is normally maintained in a closed state in which the outlet 31 of the waste gate passage 30 is closed. When the exhaust gas from the engine reaches a predetermined pressure or higher, the waste gate valve 32 is opened to open the outlet 31 of the waste gate passage 30. Change to state. As a result, a part of the exhaust gas introduced into the inlet portion 21 bypasses the main passage 23 and is guided to the concave portion 26 of the outlet portion 25, so that excessive rotation of the turbine is suppressed.

  Further, in the turbine housing 20, a space surrounded by the recess 26 is divided into a first chamber 36 in which the outlet 24 of the main passage 23 is disposed, and a second chamber 37 in which the outlet 31 of the waste gate passage 30 is disposed. A partition wall 38 is formed integrally with the bottom surface 27 and the side surface 28 of the recess 26. The partition wall 38 is disposed so as to follow the outer edge of the outlet 24 of the main passage 23 in a plan view facing the bottom surface of the recess 26, and the partition wall 38 has an end on the side surface 29 side of the recess 26. Is separated from the side surface 29, so that one communication hole 40 for communicating the first chamber 36 and the second chamber 37 is formed.

Next, the operation of the turbine housing 20 configured as described above will be described.
In the turbine housing 20 described above, since the partition wall 38 is formed in the recess 26 of the outlet portion 25, the first chamber 36 and the second chamber 37 are compared with those of the turbine housing in which the partition wall 38 is not formed. The communication area is reduced. Therefore, the exhaust gas in the second chamber 37 is less likely to be drawn into the jet of exhaust gas formed in the first chamber 36 by the reduced communication area. That is, since the vortex formed near the outlet 31 of the waste gate passage 30 becomes weak, the pressure loss of the exhaust gas caused by the vortex is reduced.

  The partition wall 38 is formed so as to follow the outlet 24 of the main passage 23 in a plan view facing the bottom surface 27 of the recess 26. Here, when the partition wall 38 is formed without following the outlet 24 of the main passage 23 in the plan view, for example, when a portion following the outlet 24 is removed on the side surface 28 side of the recess 26, the first chamber A space corresponding to the portion is formed in 36. And since the exhaust gas vortex flow is formed in the space by the jet of exhaust gas passing through the first chamber 36, the exhaust gas passing through the first chamber 36 has a pressure loss due to the vortex flow. It will be.

  In this regard, in the turbine housing 20, the partition wall 38 is formed so as to follow the outlet 24 of the main passage 23 in the plan view, so that the peripheral space of the jet is reduced. Therefore, since the vortex formed in such a space becomes small, the pressure loss due to the vortex is reduced.

  Further, only one communication hole 40 is formed in the partition wall 38. Therefore, the exhaust gas is circulated between the first chamber 36 and the second chamber 37 through one communication hole 40. Here, for example, when two communication holes 40 are provided in parallel with the partition wall 38 along the flow direction of the exhaust gas in the first chamber 36, the exhaust gas flows from the second chamber 37 to the first chamber 36. May be performed in the upstream communication hole 40, and the exhaust gas may flow from the first chamber 36 to the second chamber 37 in the downstream communication hole 40. In such a case, the flow of the exhaust gas between the first chamber 36 and the second chamber 37 is facilitated, so that the vortex formed in the second chamber 37 becomes strong, and the pressure loss of the exhaust gas caused by the vortex May increase.

  On the other hand, in the turbine housing 20, the exhaust gas is circulated between the first chamber 36 and the second chamber 37 in one communication hole 40 formed in the partition wall 38. Compared with the case where the communication hole 40 is formed, the vortex formed in the second chamber 37 is weakened. Therefore, the pressure loss generated in the exhaust gas when passing through the first chamber 36 is reduced.

  Further, since the partition wall 38 is formed integrally with the bottom surface 27 and the side surface 28 of the recess 26, compared to a case where the partition wall 38 is formed integrally only with the bottom surface 27 of the recess 26, for example. The mechanical strength of the partition wall 38 is increased.

  Incidentally, FIG. 2 and FIG. 3 show an example of simulation results performed on the turbocharger 10 described above. In this simulation, as shown in FIG. 2A, a case where an exhaust pipe that opens an opening of a recess is connected to a turbine housing in which no partition wall is formed is used as a comparative example. Further, as shown in FIG. 2B, the embodiment is a case where an exhaust pipe for closing the opening of the second chamber is connected to the turbine housing in which the partition wall is formed. And the average value of the total pressure of the exhaust gas in the upstream surface S1 just before flowing into the recessed part of an exit part and the downstream surface S2 of an exhaust pipe was computed, and the pressure loss was computed from the difference of the average value.

  As shown in FIG. 3, as a result of the above simulation, a pressure loss of about 7.1 kPa occurs in the turbocharger of the comparative example, whereas a pressure loss of about 5.8 kPa is suppressed in the turbocharger of the example. It was recognized that That is, by forming the partition wall 38, that is, by reducing the communication area between the first chamber 36 and the second chamber 37, the pressure loss of the exhaust gas after passing through the turbocharger can be reduced by this simulation. confirmed.

Next, the exhaust pipe connected to the outlet 25 of the turbine housing 20 will be described.
As shown in FIG. 4, an exhaust pipe 45 is connected to the outlet 25 of the turbine housing 20. The exhaust pipe 45 closes the opening of the second chamber 37, and in the plan view facing the bottom surface 27 of the recess 26, the center point 24 a of the outlet 24 of the main passage 23 and the outlet 31 of the waste gate passage 30. The virtual line 42 that follows the center of the exhaust pipe 45 is inclined by the connection angle θ with respect to the virtual line 41 connecting the center point 31a.

  FIG. 5 shows an example of a simulation result performed for the connection angle θ of the exhaust pipe 45 connected to the turbine housing 20. In this simulation, the connection angle θ was changed to θ = 45 °, 90 °, and 135 °, and the pressure loss of the exhaust gas generated between the upstream surface S1 and the downstream surface S2 was calculated. In Examples 1, 2, and 3, the connection angle θ corresponds to 45 °, 90 °, and 135 °. In the simulations of Examples 1, 2, and 3, conditions other than the connection angle θ are the same. is there.

  As shown in FIG. 5, as a result of the above simulation, a pressure loss of about 5.8 kPa was recognized in Example 1 in which the connection angle θ was 45 °. In Example 2 where the connection angle θ is 90 °, a pressure loss of about 5.1 kPa was observed. In Example 3 where the connection angle θ was 135 °, a pressure loss of about 4.8 kPa was observed. That is, it was confirmed that the pressure loss of the exhaust gas decreased in the order of Example 1, Example 2, and Example 3. From these facts, the connection angle θ of the exhaust pipe 45 is preferably larger than 45 °, and specifically, it is considered that the range of 90 ° to 135 ° is preferable.

  As described above, according to the turbine housing 20 of the above embodiment and the turbocharger 10 including the turbine housing 20, the effects listed below can be obtained.

  (1) The first chamber 36 and the second chamber 37 are partitioned by the partition wall 38, and the first chamber 36 and the second chamber 37 are communicated by the communication hole 40 of the partition wall 38, whereby the first chamber The communication area between 36 and the second chamber 37 is reduced. As a result, the exhaust gas flowing in the first chamber 36 is less susceptible to the vortex flow of the exhaust gas formed in the second chamber 37, and the pressure loss of the exhaust gas accompanying the passage of the turbocharger 10 is reduced.

  (2) Since the partition wall 38 is formed so as to follow the outlet 24 of the main passage 23 in a plan view facing the bottom surface 27 of the recess 26, the space around the jet of exhaust gas flowing in the first chamber 36. Becomes smaller. Thereby, since the eddy current of the exhaust gas formed in the first chamber 36 becomes weak, the pressure loss due to the eddy current is reduced.

  (3) Since the partition wall 38 is integrally formed on the bottom surface 27 and the side surface 28 of the recess 26, compared to the case where the partition wall 38 is integrally formed only on the bottom surface 27 of the recess 26, The mechanical strength of the partition wall 38 is increased.

  (4) Since one communication hole 40 is formed in the partition wall 38, the exhaust gas flows between the first chamber 36 and the second chamber 37 through the one communication hole 40. As a result, the vortex flow formed in the second chamber 37 is weaker than in the case where the plurality of communication holes 40 are formed in the partition wall 38, so that the pressure loss generated in the exhaust gas flowing through the first chamber 36 is reduced. Is done.

  (5) When the connection angle θ is in the range of 90 ° to 135 °, the pressure loss of the exhaust gas accompanying the passage of the turbocharger 10 is reduced as compared with the case where the connection angle θ is in the range of 45 ° or less.

In addition, the said embodiment can also be suitably changed and implemented as follows.
The opening of the second chamber 37 may be closed by the exhaust pipe 45 or may be opened in the exhaust pipe 45.

  A plurality of communication holes 40 may be formed in the outlet portion 25. For example, the partition wall 38 is connected only to the bottom surface 27 of the recess 26, the clearance between the side surface 28 of the recess 26 and the partition wall 38, and the clearance between the side surface 29 and the partition wall 38, thereby communicating holes May be configured.

  The partition wall 38 may be connected to the side surface 28 and the side surface 29 without being connected to the bottom surface 27 of the recess 26. That is, a communication hole may be formed in the outlet portion 25 by a gap between the bottom surface 27 of the recess 26 and the partition wall 38.

  The partition wall 38 only needs to be a wall portion that partitions the inside of the recess 26 into the first chamber 36 and the second chamber 37, and the outlet 24 of the main passage 23 or the like in the plan view facing the bottom surface 27 of the recess 26 The shape may be different from the similar shape of the outlet 24.

  The outlet portion 25 may have a shape in which the main passage 23 and the waste gate passage 30 are connected through a single partition wall. For example, the first chamber of the outlet portion 25 is formed by a cylindrical body having the same diameter as the main passage 23 extending from the main passage 23, or the second chamber of the outlet portion 25 is a waste gate passage 30 extending from the waste gate passage 30. And a cylindrical body having the same diameter. That is, the outlet portion 25 may be configured without the concave portion 26.

  -The exit part 25 should just be the structure which has the partition wall 38 inside the exit part 25 divided into a 1st chamber and a 2nd chamber, and if it is the shape mentioned above, the exit of the main channel | path 23 and a waste gate channel | path 30 outlets may be formed on different sides. In addition to the shape described above, the outlet portion 25 may have, for example, a box shape. In short, the outlet portion 25 has a space inside which the outlet of the main passage 23 and the outlet of the waste gate passage 30 are connected. I just need it.

  The waste gate valve 32 may open and close the inlet opening of the waste gate passage 30, or may open and close the waste gate passage 30 in the middle of the waste gate passage 30.

  The turbocharger 10 may be provided with an opening / closing valve that opens and closes the communication hole 40 according to the opening / closing of the waste gate valve 32. According to such a configuration, when the waste gate valve 32 is in the closed state, the first chamber 36 and the second chamber 37 are isolated, and the pressure loss of the exhaust gas is further reduced.

  The engine on which the turbocharger 10 is mounted may be a gasoline engine.

  θ ... connection angle, 10 ... turbocharger, 11 ... compressor part, 12 ... turbine part, 20 ... turbine housing, 21 ... inlet part, 22 ... scroll part, 23 ... main passage, 24 ... outlet, 24a ... center point, 25 ... exit part, 26 ... recess, 27 ... bottom surface, 28,29 ... side face, 30 ... waste gate passage, 31 ... exit, 31a ... center, 32 ... waste gate valve, 36 ... first chamber, 37 ... second chamber 38 ... partition walls, 40 ... communication holes, 41 ... imaginary lines, 45 ... exhaust pipes.

Claims (6)

A main passage in which the turbine wheel is accommodated by connecting the inlet portion and the outlet portion;
A wastegate passage connecting the inlet and the outlet to bypass the turbine wheel;
The outlet portion is
A partition wall that partitions the flow path of the outlet portion into a first chamber and a second chamber;
A communication hole formed in the partition wall for communicating the first chamber and the second chamber;
An outlet of the main passage opens into the first chamber;
An outlet of the waste gate passage is open to the second chamber. The outlet portion is
An outlet of the main passage and an outlet of the waste gate passage are formed on the bottom surface of the recess formed on the end face of the outlet flange, and a waste gate valve is disposed on the bottom surface,
The turbine housing according to claim 1, wherein the flow path of the outlet portion is the concave portion. The turbine housing according to claim 2, wherein the partition wall is formed so as to follow the shape of the outlet of the main passage in a plan view facing the bottom surface. The turbine housing according to claim 2, wherein the partition wall is connected to a bottom surface of the recess and a side surface of the recess. The turbine housing according to any one of claims 1 to 4, wherein the number of the communication holes is one. A main passage in which the turbine wheel is accommodated by connecting the inlet portion and the outlet portion;
A turbine housing comprising a wastegate passage connecting the inlet and the outlet to bypass the turbine wheel;
The outlet portion is
A partition wall that partitions the flow path of the outlet portion into a first chamber and a second chamber;
A communication hole formed in the partition wall for communicating the first chamber and the second chamber;
An outlet of the main passage opens into the first chamber;
The turbocharger, wherein an outlet of the waste gate passage is open to the second chamber.