JP2007278130A - Turbine housing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration in turbine efficiency, in a turbine housing of a turbocharger having an inner housing and an outer housing covering the inner housing through a gap. <P>SOLUTION: The turbine housing 10 has the inner housing 24, and the outer housing 26 covering the inner housing 24 through the gap. The inner housing 24 has an inner split part P1 at an axially intermediate portion of a scroll chamber S2, and the outer housing 26 has an outer split part P2 at the axially intermediate portion of the scroll chamber S2. In the turbine housing 10, a connecting member 42 connects the inner housing 24 with the outer housing 26 at the axially intermediate portion of the scroll chamber S2 while maintaining a gap G therebetween, and the connecting member 42 is joined while being interposed between the inner split part P1 and the outer split part P2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a turbine housing, and more particularly, to a turbine housing of a turbocharger including an inner housing and an outer housing that covers the inner housing with a gap.

  As a turbine housing of the turbocharger, a cast housing is generally used. On the other hand, for example, Patent Document 1 proposes a turbine housing manufactured by a press-formed product of a steel plate. This is provided with an inner housing and an outer housing made of a heat-resistant thin steel plate, and has a structure in which the inner housing is covered by the outer housing through a gap. In this turbine housing, the outer housing and the inner housing are held so that most of them are separated from each other by a plurality of locking members made of a metal mesh at a predetermined interval.

  Furthermore, Patent Document 2 discloses another example of a turbine housing manufactured by a press-formed product of a steel plate. In this, the inner housing encapsulated by the outer housing through a gap is divided and formed so as to be halved, and the halved divided portions are combined in a slidable state. It can be opened and closed. A SUS mesh is interposed between the inner housing and the outer housing in order to maintain a gap therebetween at a predetermined interval.

  On the other hand, a turbine housing having a member protruding toward the scroll chamber has also been proposed. For example, in Patent Document 3, a thin plate formed body is disposed on the inner wall surface of a cast turbine housing via a ceramic heat insulating layer, and a flat plate extending from the turbine housing to the nozzle portion so as to form a turbine scroll having different passage areas. And a turbine housing in which the scroll chamber is divided into two parts is disclosed. In this structure, the joint between the thin plate molded body and the flat plate is melted by casting at the time of producing the turbine housing, and they are integrally fused. Further, Patent Document 4 discloses a turbine housing in which a partition plate sandwiched between left and right portions of a turbine housing body is welded together with the left and right portions.

Japanese Patent Laid-Open No. 2003-29379 JP 2002-349275 A JP 63-1111234 A Japanese Utility Model Publication No. 64-51734

  In a turbine housing having a double shell structure with a gap in between, in order to reduce thermal fatigue or the like of the inner housing due to expansion or contraction due to heat of exhaust gas, for example, end portions of members constituting the inner housing, etc. Is preferably slidable freely. On the other hand, if this is done, the expansion and contraction of the inner housing will repeatedly occur due to long-term use, resulting in a deviation in the positional relationship between the inner housing and the outer housing, the size of the gap between them, etc. May change. When such a situation occurs, it may be difficult to maintain high efficiency of the turbine.

  Accordingly, the present invention provides a turbine housing for a turbocharger turbine housing that includes an inner housing and an outer housing that covers the inner housing with a gap, and that can prevent a reduction in turbine efficiency. For the purpose.

  In addition, the thing of the said patent document 3 and the said patent document 4 is not a turbine housing which has a double shell structure with a clearance gap between them. That is, no gap is maintained outside the scroll chamber in them. Therefore, they do not solve the above problems.

  In order to achieve the above object, a turbine housing according to the present invention includes an inner housing and an outer housing that covers the inner housing through a gap, and the inner housing is an intermediate portion in the axial direction of the scroll chamber. And the outer housing has an outer divided portion at an axially intermediate portion of the scroll chamber, and the inner housing and the outer housing are connected in the axial direction of the scroll chamber while maintaining the gap. The connecting member connected at the intermediate portion is joined while being sandwiched between the inner divided portion and the outer divided portion.

  According to the above configuration, the connecting member that connects the inner housing and the outer housing at the intermediate portion in the axial direction of the scroll chamber is joined while being sandwiched between the inner divided portion and the outer divided portion while maintaining the gap. Therefore, the inner housing is fixed in the outer housing via the connecting member while maintaining a predetermined interval. As a result, the inner housing and the outer housing are prevented from being displaced even if the inner housing has a slidable free portion and the heat of the exhaust gas repeatedly expands and contracts in the inner housing. Is done. That is, the size of the gap between them is kept unchanged. Therefore, it is possible to prevent a decrease in turbine efficiency.

  Preferably, the connecting member has a plate shape. Since the connecting member has a plate shape, the inner housing is firmly fixed in the outer housing over a wide range of the axially intermediate portion of the scroll chamber when it is sandwiched and joined between the inner divided portion and the outer divided portion. .

  Further, in this case, the connecting member may extend inward of the inner housing and partition the scroll chamber so as to be divided into two in the axial direction, so that the scroll chamber has a twin scroll shape. This makes it possible to form a turbine housing having a twin scroll-shaped scroll chamber easily and inexpensively.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the turbine housing which concerns on the following embodiment is applied to the radial type turbine of the turbocharger for vehicles.

  The external view of the turbine housing 10 of 1st embodiment is shown in FIGS. 1 is a right side view of the turbine housing 10, FIG. 2 is a left side view thereof, FIG. 3 is a front view thereof, and FIG. 4 is a rear view thereof. 1 and 2 show the flow of exhaust gas with white arrows. Exhaust gas from an engine (not shown) enters the turbine housing 10 from the lower inlet 12 in FIGS. 1 and 2, turns at a right angle in the turbine housing 10, and exits the turbine from the outlet 14 along the turbine axial direction. It is discharged out of the housing 10. An inlet side flange portion 16 is provided in the vicinity of the inlet 12, and the inlet side flange portion 16 is used for connection to an exhaust pipe or an exhaust manifold (not shown) on the engine side. An outlet side flange portion 18 is provided in the vicinity of the outlet 14, and the outlet side flange portion 18 is used for connection to an exhaust pipe (not shown) on the downstream side. A center flange portion 22 used for connection with the center housing 20 (see FIG. 6) is also provided.

  Cross-sectional views of the turbine housing 10 are shown in FIGS. FIG. 5 is a cross-sectional view taken along line AA in FIG. 1, in other words, a cross-sectional view taken along a plane orthogonal to the turbine axis L. FIG. 5 shows the inner housing 24, the outer housing 26, and the inlet flange portion 16. FIG. 6 is a cross-sectional view taken along line BB in FIG. 3, in other words, a cross-sectional view cut along a plane including the turbine shaft L.

  As understood from these drawings, the turbine housing 10 includes a sheet metal inner housing 24 and an outer housing 26 that can be press-molded together, and has a so-called double shell structure. The inner housing 24 substantially defines an exhaust gas flow path inside the housing. The outer housing 26 forms an outer shell or structure that covers the inner housing 24 via the gap G, protects the inner housing 24, and at the same time insulates it, and also plays a role of increasing rigidity as the turbine housing 10. The exhaust gas flow path mainly partitioned by the inner housing 24 is composed of an inlet 12, an approach chamber S1, a scroll chamber S2, a turbine wheel chamber S3, an outlet chamber S4, and an outlet 14 in this order from the upstream side. A turbine wheel chamber S3 is formed inside the scroll chamber S2 in the radial direction, and a turbine wheel 28 (see FIG. 6) is rotatably accommodated in the turbine wheel chamber S3.

  However, in this first embodiment, as will be described later, the inlet 12 is composed of a first inlet 12a and a second inlet 12b, and the run-up chamber S1 is composed of a first run-up chamber S1a and a second run-up chamber S1b. The scroll chamber S2 includes a first scroll chamber S2a and a second scroll chamber S2b.

  As shown in FIG. 6, the center flange portion 22 of the turbine housing 10 is connected and fixed to one end of the center housing 20. For this fixing, a fastener 30 having a U-shaped cross section and a ring shape as shown in the drawing is used. A compressor housing (not shown) is connected and fixed to the other end of the center housing 20, and a compressor wheel coaxially connected to the turbine wheel 28 by the turbine shaft 32 is accommodated in the compressor housing.

  The inner housing 24 of the first embodiment is divided and formed from four members: a first inner housing member 34, a second inner housing member 36, a first running member 38, and a second running member 40. Yes. The first inner housing member 34 and the second inner housing member 36 are joined while sandwiching a plate-like member 42 described later (see FIG. 6). Thereby, the scroll chamber S <b> 2 is partitioned and formed inside the first inner housing member 34 and the second inner housing member 36. On the other hand, in the first embodiment, the run-up chamber S1 communicating with the upstream side of the scroll chamber S2 is defined by two members, the first run-up member 38 and the second run-up member 40.

  The inner housing 24 has a divided portion P1 at an intermediate portion in the direction of the turbine axis L of the scroll chamber S2 (hereinafter, referred to as “axial intermediate portion”), and the scroll chamber S2 is formed by the divided portion P1. The first inner housing member 34 and the second inner housing member 36 to be formed are divided. The division position along the turbine axis L of the first inner housing member 34 and the second inner housing member 36 is in the vicinity of the outermost diameter position of the scroll chamber S2, and is a position where the scroll chamber S2 is divided in half. The divided portion P1 located on a plane substantially orthogonal to the turbine axis L is composed of a first inner divided portion 34P of the first inner housing member 34 and a second inner divided portion 36P of the second inner housing member 36. A plate-like member 42, which will be described in detail later, is joined between them, that is, sandwiched between the divided portions P1 (see FIG. 6). Hereinafter, in this specification, the division part P1 in the inner housing 24 is referred to as an “inner division part”. The first inner housing member 34 is located on the outlet front end side in the direction of the turbine axis L with respect to the second inner housing member 36.

  The first inner housing member 34 and the second inner housing member 36 are each produced by press-molding a metal plate material. That is, since they are made of sheet metal, they can be manufactured relatively easily and inexpensively. The thickness of the metal plate material is, for example, 0.4 mm to 2.0 mm, and a material that is thinner than the metal plate material forming the outer housing 26 is used. As the metal plate material of the first inner housing member 34 and the second inner housing member 36, a material excellent in corrosion resistance and heat resistance is adopted, for example, stainless steel, preferably austenitic stainless steel is used.

  As shown in FIG. 5, the inner housing 24 is provided with a tongue-like tongue T so as to form a flow path of exhaust gas from the running chamber S1 to the scroll chamber S2. As shown in FIG. 7, the tongue T has convex flat tongue portions 44, 46 formed on the first and second inner housing members 34, 36, facing each other via the plate-like member 42. It is formed by joining the surfaces 44a and 46a and fixing them by welding or the like. The end portions of the plate-like member 42 to be joined in such a manner are stepped so that the tongue portions 44 and 46 can be fitted well (see FIG. 7). FIG. 8 shows a diagram in which the plate-like member 42 is overlapped with the cross-sectional view of FIG. From FIG. 8, it is clear that the plate-like member 42 divides the scroll chamber S2 into two in the axial direction.

  In the first embodiment, the plate-like member 42 is used as a connecting member that is sandwiched and joined by the inner divided portion P1. The plate-like member 42 is annular, has a size that slightly protrudes from the outer housing 26 to the outside, and has a through hole having a diameter slightly larger than the outer diameter of the turbine wheel 28, that is, the diameter of its rotating contour, near the center. 42a. Therefore, as shown in FIG. 6, the turbine wheel 28 is rotatably positioned in the through hole 42 a in a state where the turbine wheel 28 is accommodated in the turbine housing 10. The plate-like member 42 is sandwiched between the inner divided portions P1 of the intermediate portion in the axial direction of the scroll chamber S2 and attached so as to extend on a surface substantially orthogonal to the turbine shaft L. The plate-like member 42 extends inward of the inner housing 24. The plate-like member 42 extends inward to the reduced diameter nozzle portion S5 located at the boundary between the scroll chamber S2 and the turbine wheel chamber S3. Therefore, the plate-like member 42 partitions the scroll chamber S2 so as to be divided into two in the axial direction, and makes the scroll chamber S2 into a twin scroll shape. That is, the scroll chamber S2 is divided into two by a plane substantially orthogonal to the turbine axis L, and is constituted by two scroll chambers S2a and S2b. The two scroll chambers S2a and S2b are formed by the first scroll chamber S2a formed by the plate-like member 42 and the first inner housing member 34, and the plate-like member 42 and the second inner housing member 36. The second scroll chamber S2b.

  The plate-like member 42 of the first embodiment is provided with a communication hole 42b so that the gap G is not completely separated by the plate-like member 42 into two regions (see FIG. 8). Although three communication holes 42b are provided in FIG. 8, the present invention does not limit the number of communication holes 42b. The communication hole 42b may not be provided.

  The plate-like member 42 is made of a metal plate material. The plate-like member 42 is manufactured by being punched to have the above-described shape, and is kept in a plate shape without being generally curved. Therefore, the plate-like member 42 is manufactured at a low cost. The thickness of the metal plate material is, for example, 0.4 mm to 2.0 mm, but is preferably thicker than the metal plate material forming the inner housing 24. As the metal plate material, a material excellent in corrosion resistance and heat resistance is adopted, and for example, stainless steel, preferably austenitic stainless steel is used.

  The first running member 38 and the second running member 40 are respectively tubular members. As shown in FIG. 9 when the inlet flange portion 16 attached to the turbine housing 10 is viewed in the direction of the white arrow on the inlet side in FIG. 1, the inlet 12 includes two first inlets 12a and second inlets 12b. It is made up of. In the first embodiment, the first run-up member 38 and the second run-up are such that the first run-up chamber S1a and the second run-up chamber S1b are communicated with the first entrance 12a and the second entrance 12b, respectively. A member 40 is arranged. Further, as described above, the first run-up member 38 and the second run-up chamber S1b communicate with the two scroll chambers S2a and S2b divided by the plate-like member 42, A second running member 40 is arranged. The first running member 38 and the second running member 40 are fitted into the first housing member 34 and the second inner housing member 36, respectively, and the fitting portions are joined to each other. In the first embodiment, the two inlets 12a and 12b and the two scroll chambers S2a and S2b have a positional relationship that is rotated by approximately 90 °. Each shape is twisted by 90 ° (see FIG. 2 and FIG. 5).

  The tubular members of the first run-up member 38 and the second run-up member 40 are produced by joining members that are press-molded products that are substantially halved in the longitudinal direction. That is, they are made of sheet metal and can be manufactured relatively easily and inexpensively. The thickness of the metal plate material is, for example, 0.4 mm to 2.0 mm, and a material having substantially the same thickness as the metal plate material forming the first inner housing member 34 and the second inner housing member 36 is used. As the metal plate material of the first run-up member 38 and the second run-up member 40, those excellent in corrosion resistance and heat resistance are adopted, and for example, stainless steel, preferably austenitic stainless steel is used. In addition, the 1st run-up member 38 and the 2nd run-up member 40 may each be produced by twisting and processing a tubular member, or the fluid pressure forming which shape | molds by making a fluid pressure act on a tubular member (For example, hydroforming) may be used.

  The outer housing 26 of the first embodiment is divided and formed from a first outer housing member 48 and a second outer housing member 50. They are joined with the plate-like member 42 interposed therebetween. Similar to the inner housing 24, the outer housing 26 has a split portion P <b> 2 at an axially intermediate portion. That is, the division position along the turbine axis L that makes the outer housing 26 the first outer housing member 48 and the second outer housing member 50 is near the outermost diameter position of the scroll chamber S2, and the scroll chamber S2 is It is a position that divides in half. The divided portion P <b> 2 located on a surface substantially orthogonal to the turbine shaft L is composed of a first outer divided portion 48 </ b> P of the first outer housing member 48 and a second outer divided portion 50 </ b> P of the second outer housing member 50. . The plate-like member 42 is sandwiched and joined between them. Hereinafter, in this specification, the division part P2 in the outer housing 26 is referred to as an “outer division part” with respect to the inner division part P1 of the inner housing 24. The first outer housing member 48 is positioned closer to the outlet front end side in the direction of the turbine axis L than the second outer housing member 50.

  The first outer housing member 48 and the second outer housing member 50 are each produced by press-molding a metal plate material. That is, since they are made of sheet metal, they can be manufactured relatively easily and inexpensively. The thickness of the metal plate material is thicker than that of the inner housing 24, and is, for example, 1.5 mm to 2.5 mm. As the metal plate material of the outer housing 26, a material excellent in corrosion resistance and heat resistance is adopted. For example, stainless steel, preferably ferritic stainless steel is used. The outer housing 26 according to the present invention is not limited to such a configuration, size, material, and the like. However, since the outer housing 26 is an outer shell of the turbine housing 10, it is required to have a certain level of strength and rigidity.

  As described above, the plate-like member 42 as the connecting member is sandwiched between the inner divided portion P1 of the inner housing 24 and is also sandwiched and joined to the outer divided portion P2 of the outer housing 26. The plate-like member 42 extends inward to the scroll chamber S <b> 2 and extends outward to the outer housing 26. In the first embodiment, the plate-like member 42 extends outward to such an extent that it has an end protruding outward from the outer housing 26. The plate-like member 42 is joined by being sandwiched between the inner divided portion P1 and the outer divided portion P2 across the gap G formed between the inner housing 24 and the outer housing 26 located at the outer peripheral portion of the scroll chamber S2. Has been. As a result, the inner housing 24 and the outer housing 26 are connected by the plate-like member 42. Therefore, the positional relationship between the inner housing 24 and the outer housing 26 and the gap G between them are kept constant.

  As shown in FIG. 5 and FIG. 10, the inlet side flange portion 16 is manufactured by pressing a thick metal plate material (5 mm to 15 mm), for example. Here, the inlet side end portion 52 of the outer housing 26 is inserted into the inlet side flange portion 16 and fixed by welding or the like. The inlet flange portion 16 is provided with a step 54 for positioning the inlet end 52 of the outer housing 26.

  On the other hand, the inlet-side end portion 56 of the inner housing 24 is simply slidably fitted inside the inlet-side end portion 52 of the outer housing 26, so that the inner housing 24 and the outer housing 26 are connected to each other. The thermal deformation difference is absorbed. That is, when the turbine is operating, the inner housing 24 directly receives the heat of the exhaust gas and becomes a high temperature. Therefore, the inner housing 24 has a larger thermal expansion amount than the outer housing 26. The difference in thermal expansion at this time is absorbed by the sliding movement of the inlet side end portion 56 of the inner housing 24 with respect to the inlet side end portion 52 of the outer housing 26. Thereby, the shape of the flow path in the inner housing 24 is maintained, and the stress acting on the inner housing 24 is relieved. In other words, this slide portion is a relief for the inner housing 10 for absorbing the difference in thermal expansion. Such a slide portion is also provided on the outlet side, which will be described later. In the turbine housing 10, the inner housing 24 is slidably supported at at least two locations on the inlet side and the outlet side. When viewed microscopically, the slide portion has a gap at the boundary between the members, and a small amount of exhaust gas passes through the gap. This point will be described in detail later. The gap on the entrance side is exaggerated in FIG. 10 and is indicated by G1, and this gap G1 communicates with the main gap G. The gap G1 is, for example, 0.1 mm to 0.25 mm.

  Further, as shown in FIG. 6, the outer housing 26 is connected and fixed to the center flange portion 22 by welding or the like. However, in the first embodiment, the center side end portion 58 of the inner housing 24 is not fixed to the inner end surface 60 of the center flange portion 22 but is in contact therewith. Therefore, in the turbine housing 10, the inner housing 24 is slidably supported with respect to the outer housing 26 and the center flange portion 22 even on the center flange side. Therefore, in the turbine housing 10 of the first embodiment, the inner housing 24 is slidably supported at three locations on the inlet side, the outlet side, and the center flange side. The inner housing 24 may be joined to at least one of the outer housing 26 and the center side flange portion 22 on the center flange side.

  On the outlet side of the turbine housing 10, the outlet side flange portion 18 is attached to the outlet side end portion 62 of the outer housing 26 via an outlet pipe 64 (see FIG. 6). The outlet side end portion 62 of the outer housing 26 has a cylindrical shape as a whole and is formed in a crank shape so that the end portion 62a is reduced in diameter, and one end portion of the outlet pipe 64 is fitted outside the end portion 62a. And fixed by welding or the like. The other end portion of the outlet pipe 64 is bent at a right angle by pressing or the like, and a flat plate ring-shaped outlet side flange portion 18 is fixed thereto by welding or the like. The outlet side flange portion 18 can be produced by cutting or casting a pipe material. The outlet chamber S4 and the outlet 14 are formed by the outlet pipe 64 and the outlet side flange portion 18.

  Further, the turbine housing 10 of the first embodiment includes a shroud member 66 for surrounding the shroud portion 28 a of the turbine wheel 28. The shroud member 66 is formed in a cylindrical shape, and has a flare shape in which the upstream side portion 66a follows the shroud curve of the shroud portion 28a of the turbine wheel 28. The downstream end portion 66b of the shroud member 66 is fitted inside the end portion 62a of the outer housing 26 and is fixed by welding or the like over the entire circumference. As a result, the shroud member 66 has a center on the turbine axis L and is disposed coaxially with the cylindrical outlet side end portion 62 of the outer housing 26.

  The shroud member 66 is made of a tube material, and can be easily and inexpensively manufactured by bending the tube material by press working. The clearance (tip clearance) between the shroud portion 28a of the turbine wheel 28 and the shroud member 66 is important because it affects the turbine efficiency. Therefore, in order to keep the tip clearance with high accuracy, the surface of the shroud member 66 facing the shroud portion 28a is finished with high accuracy by machining. However, if accuracy can be obtained only by bending, machining may be omitted. The thickness of the tube material forming the shroud member 66 is thicker than the inner housing 24 in consideration of machining allowance when machining (for example, about 1.5 mm to 3.0 mm), and the inner housing when machining is not performed. Thicker than 24 or equivalent. In addition, when the thickness of the shroud member 66 is increased, the rigidity thereof is increased, and thermal deformation during operation is suppressed. Since the high-temperature exhaust gas passes inside the shroud member 66, the shroud member 66 is made of a material excellent in heat resistance and corrosion resistance, for example, stainless steel. A turbine wheel chamber S3 is formed in the inner direction of the shroud member 66.

  When the shroud member 66 is assembled to the outer housing 26 in this way, a ring-shaped gap G <b> 2 is formed between the outer housing 26 and the shroud member 66. The gap G2 is closed with respect to the outlet side of the turbine wheel 28, that is, the outlet chamber S4 and the outlet 14, by the fixing portion, that is, the closing portion between the outlet side end portion 66b of the shroud member 66 and the end portion 62a of the outer housing 26, and The upstream side of the turbine wheel 28, that is, the scroll chamber S2, is opened. The outlet side end portion 68 of the inner housing 24 is inserted into the gap G2. The outlet side end portion 68 of the inner housing 10 is formed to project from the scroll chamber forming portion 34a of the first inner housing member 34, which forms the reduced diameter nozzle portion S5, toward the outlet side, and is formed in a cylindrical shape as a whole. And a curved shape along the outer peripheral surface of the shroud member 66. And the front-end | tip part of the exit side edge part 68 is inserted in the clearance gap G2. In this insertion portion, the outlet side end portion 68 is slidable, that is, the inner peripheral surface of the outlet side end portion 68 is slidable with respect to the outer peripheral surface of the shroud member 66, and the outer peripheral surface of the outlet side end portion 68 is outside. The housing 26 is slidable with respect to the inner peripheral surface of the outlet side end 62.

  Thus, the outlet side end portion 68 of the inner housing 24 is supported so as to be slidable in the direction of the turbine axis L, and a slide support portion that absorbs a thermal deformation difference between the inner housing 24 and the outer housing 26 is also formed on the turbine outlet side. Will be. Even in this slide support portion, there is a gap at the boundary between the members when viewed microscopically. As exaggeratedly shown in FIG. 11, the gap is a gap G3 between the outlet side end portion 68 and the outer housing 26 and a gap G4 between the outlet side end portion 68 and the shroud member 66. The gaps G3 and G4 are, for example, 0.1 mm to 0.25 mm. There is also a relatively large gap G5 in the axial direction between the outlet side end portion 68 and the closing portion, and the movement of the outlet side end portion 68 is sufficiently allowed by this gap G5.

  Eventually, as shown in FIG. 11, a U-turn channel is formed by the gaps G3, G5, G4, and this channel is located upstream of the main gap G between the inner housing 24 and the outer housing 26. The end is connected in communication and the downstream end thereof is connected in communication with the scroll chamber S2 immediately before the leading edge portion 28b of the turbine wheel 28.

  Next, the operation and effect of the turbine housing 10 of the first embodiment will be described in detail.

  During operation of the turbocharger, exhaust gas from the engine enters the turbine housing 10 through the inlet 12, enters the turbine wheel chamber S3 through the run-up chamber S1 and the scroll chamber S2, and rotates the turbine wheel 28 here. To do. Then, it discharges | emits from the exit 14 through exit chamber S4. The compressor wheel is rotationally driven by the rotational drive of the turbine wheel 28, and air is supercharged to the engine.

  On the other hand, the exhaust gas may flow into the gap G from the gap G1 shown in FIG. As shown by the arrow in FIG. 11, the exhaust gas reaches the outlet-side gap G <b> 2 and returns to the upstream side of the turbine wheel 28 through the gaps G <b> 3, G <b> 5, G <b> 4 in order. Since the gap G2 is closed to the outlet side of the turbine wheel 28, the exhaust gas flowing into the gap G can pass through the turbine wheel 28 (between the outer peripheral surface of the shroud portion 28a and the inner peripheral surface of the shroud member 66). Without leaking to the exit chamber S4 side. On the other hand, since the gap G <b> 2 is opened on the upstream side of the turbine wheel 28, all the exhaust gas flowing into the gap G is used for driving the turbine wheel 28. Eventually, all the exhaust gas flowing into the gap G can be collected and used for driving the turbine wheel 28 without being wasted, so that it is possible to prevent a decrease in turbine efficiency.

  Although the center side end portion 58 of the inner housing 24 is slidable also on the center housing side, the exhaust gas temporarily leaks from between the center side end portion 58 of the inner housing 24 and the center side flange portion 22. Even if there is, the slide portion is located in the nozzle portion S5, so that the exhaust gas appropriately reaches the turbine wheel 28.

  Further, since the shroud member 66 is made by appropriately processing a pipe material, it can be easily and inexpensively produced. However, the shroud member may be made of a material other than a pipe material, for example, a cast product. The shroud member 66 is fixed only at the outlet side end portion 66b thereof, and the upstream side end portion on the opposite side can be thermally expanded and contracted. Thereby, the thermal stress of the shroud member 66 can also be relieved. Further, since the shroud member 66 has an axially symmetric cylindrical shape, thermal deformation also becomes axially symmetric, that is, only expands or contracts the diameter. Therefore, it is possible to maintain the tip clearance well over the entire circumference. Further, since the shroud member 66 is a member separate from the inner housing 24, even if the inner housing 24 deteriorates due to repeated thermal deformation or the like, the influence does not reach the shroud member 66, and the chip clearance is affected. Absent. Accordingly, it is possible to avoid a decrease in turbine performance due to the deterioration of the inner housing 24.

  As described above, the outlet-side end portion 68 of the inner housing 24 inserted into the gap G2 is movable. Therefore, even if the inner housing 24 expands due to heat from the exhaust gas, the outlet-side end portion of the inner housing 24 is expanded. When the portion 68 moves (that is, escapes), stress on the inner housing 24 is relieved, and deterioration of the turbine housing 10 is suppressed. That is, if the outlet side end portion 68 is fixed and restrained to the outer housing 26 or the like, the turbine housing 10 will be deteriorated due to the stress when the inner housing 24 is thermally expanded. Further, since the outlet side end portion 68 of the inner housing 24 moves in the turbine axis L direction to buffer the thermal expansion and thermal contraction of the inner housing 24, the radial extension of the inner housing 24 is suppressed. Even if a radially inward overhang of the inner housing 24 may occur, a strong shroud member 66 exists around the turbine wheel 28 to protect the turbine wheel 28 and thus to the turbine wheel 28 of the inner housing 24. Is reliably prevented.

  Similarly, since there is a slide support portion for the inner housing 24 on the inlet side of the turbine housing 10, the stress during the thermal expansion of the inner housing 24 is relieved by the extension of the inner housing 24 toward the running chamber, and the turbine Deterioration of the housing 10 is suppressed. Of course, the same applies to the center flange side.

  Further, the turbine housing 10 has a double shell structure as described above. Therefore, the thickness of the housing (in the case of the first embodiment, the total thickness of the inner housing 24 and the outer housing 26) can be reduced as compared with the case where the turbine housing is an integral casting. Moreover, the heat insulation effect is exhibited by the gap G, and heat dissipation from the inside of the inner housing 24 to the outside is suppressed. Therefore, heat is suppressed from being removed from the exhaust gas in the turbine housing 10, and higher temperature exhaust gas is discharged from the turbine housing 10. When there is an exhaust purification catalyst on the downstream side of the turbine housing 10, it is possible to contribute to early activation of the catalyst after engine cold start. In addition, since the thickness of the housing is reduced, the supercharger can be reduced in weight, which leads to improved fuel efficiency. When the gap G between the inner housing 24 and the outer housing 26 is filled with a member such as ceramic wool, deformation of the inner housing 24 can be suppressed at the same time as filling the space, and further, exhaust gas to the gap G can be suppressed. Inflow can also be suppressed, and degradation of turbine performance is suppressed even under relatively severe use conditions (such as when the exhaust gas temperature is high).

  Further, in the first embodiment, the plate-like member 42 is provided as the connecting member, so that the inner housing 24 is firmly fixed in the outer housing 26. Therefore, as described above, even if the various end portions 56, 58, 68 of the inner housing 24 are slidably supported with respect to the outer housing 26, The housing 24 is prevented from shifting. Accordingly, even if the inner housing 24 is heated and expanded by the heat of the exhaust gas and then repeatedly cooled and contracted due to the stop of the engine or the like, the gap G between the inner housing 24 and the outer housing 26 is repeatedly generated. In addition, various clearances (chip clearances) such as the gaps G1 to G5 can be maintained at predetermined intervals for a long time. By providing the plate-like member 42 as the connecting member in this manner, the relative positional relationship between the inner housing 24 and the outer housing 26 is maintained without change even if the inner housing 24 is repeatedly expanded and contracted. Therefore, the deterioration of the turbine housing 10 is further suppressed, and the performance of the turbine housing 10 can be maintained at a high performance for a long period. That is, it is possible to prevent a decrease in turbine efficiency. Therefore, the reliability of the turbine having the turbine housing 10 is improved because the turbine housing 10 exhibits high performance.

  As described above, in the first embodiment, the connecting member is a plate-like member. However, since the plate-like member is manufactured using sheet metal as described above, the turbine housing can be manufactured at a low cost even if the connecting member is provided. To be kept. Further, since the plate-like member 42 has no stress concentration portion such as a bent portion, the turbine housing 10 does not deteriorate from this member. In order to further improve the reliability, for example, the stepped shape as described above, that is, the stepped shape for fitting and positioning with the tongue portions 44 and 46 may not be provided in the plate-like member 42.

  Further, in the turbine housing 10 as described above, two inlets 12, an auxiliary chamber S1, and two scroll chambers S2 are formed, thereby forming a partition by the first inlet 12a, the first auxiliary chamber S1a, and the first scroll chamber S2a. The first flow path Sa and the second flow path Sb defined by the second inlet 12b, the second auxiliary chamber S1b, and the second scroll chamber S2b are formed. These flow paths Sa and Sb are opened corresponding to the operating state of the engine. For example, when the engine speed is low, exhaust gas is guided to the turbine wheel 28 using the first flow path Sa. When the engine speed is high, the first flow path Sa and the second flow path Sb A control valve (not shown) provided on the upstream side of the second inlet 12b is controlled to open and close so that the exhaust gas is guided to the turbine wheel 28 using both flow paths. As described above, in the first embodiment, the control valve is disposed on the upstream side of the turbine. However, the control valve may be disposed in the turbine, for example, in the second running member 40.

  As mentioned above, although the turbine housing which concerns on this invention was demonstrated based on 1st embodiment, this invention is not limited to this. For example, although the connecting member is the plate-like member 42 in the first embodiment, the present invention includes various types of connecting members. The connecting member may be sandwiched and joined between the inner divided portion P1 and the outer divided portion P2, and the outer housing 26 and the inner housing may be connected while maintaining the gap G.

  In the first embodiment, the inner housing 24 is composed of four members: a first inner housing member 34, a second inner housing member 36, a first running member 38, and a second running member 40. However, the inner housing 24 may be constituted by the first inner housing member 34 and the second inner housing member 36. In such a case, as in the first embodiment, if the scroll chamber S2 is divided into two in the axial direction to form a twin scroll shape, the plate-like member is divided into the auxiliary chamber S1 in two in the axial direction. 42 may extend to the vicinity of the inlet 12. Thus, the first flow path Sa and the second flow path Sb are formed in the same manner as in the first embodiment, but the entrance and exit of the run-up chamber S1a and the entrance and exit of the run-up chamber S1b are Each communicates without twisting by 90 °.

  By the way, if the scroll chamber S2 is not formed into a twin scroll shape, a connecting member that does not extend to the scroll chamber S2 may be provided. Next, the turbine housing 110 having such a connecting member will be described as a second embodiment of the present invention. The turbine housing 110 is different from the turbine housing 10 of the first embodiment mainly in connection members, and accordingly, the inlet 12, the run-up chamber S1, and the scroll chamber S2 are formed one by one. . Hereinafter, differences will be mainly described, and common points are denoted by the same reference numerals in the drawings, and description thereof will be omitted. The appearance of the turbine housing 110 of the second embodiment is substantially the same as the appearance of the first embodiment shown in FIGS. 1 to 4. 12 is a view corresponding to the cross-sectional view taken along the line AA of FIG. 1 (the view corresponding to FIG. 8 of the first embodiment), and FIG. 13 is a cross-sectional view corresponding to the line BB of FIG.

  The turbine housing 110 includes a horseshoe-shaped member 112 as a connecting member. The horseshoe-shaped member 112 extends to the vicinity of the inlet 12, and is divided into an inner middle portion P3 of the inner housing 124 including a first inner housing member 134 and a second inner housing member 136 that are divided at an axially intermediate portion, and an outer housing. It is sandwiched and joined by 26 outer division parts P2. The horseshoe-shaped member 112 extends so as to substantially cross the gap G. However, the horseshoe-shaped member 112 hardly extends into the scroll chamber S2, and is simply between the inner divided portion P3 and the outer divided portion P2. It extends and is joined while being sandwiched between them. And since the horseshoe-shaped member 112 is made not to extend in the inner housing 124 in general, it is discontinuous in the approach chamber S1. Therefore, in the turbine housing 110 of this modification, the entrance 12, the run-up chamber S1, and the scroll chamber S2 are each one.

  Note that the horseshoe-shaped member 112 in FIG. 12 does not reach the tongue T portion. The tongue T is formed by fitting and joining the first inner housing member 134 and the second inner housing member 136 to each other, so that the exhaust gas can be appropriately guided from the run-up chamber S1 to the scroll chamber S2. It is. However, the present invention does not exclude that the horseshoe-shaped member 112 extends to the tongue T like the plate-like member 42 of the first embodiment.

  Next, a turbine housing 210 provided with still another connecting member will be described as a third embodiment of the present invention. The turbine housing 210 has a connecting member different from that of the turbine housing 110 of the second embodiment, and accordingly, the appearance is slightly different. Here, as a view corresponding to the cross-sectional view taken along line AA of FIG. 1, FIG. 14 shows a cross-sectional view of the turbine housing 210, and only the differences will be described, and the other description will be omitted.

  The turbine housing 210 includes a plurality of rod-like members 212 as connecting members. The plurality of rod-like members 212 are sandwiched and joined between the inner divided portion P4 of the inner housing 224 and the outer divided portion P2 of the outer housing 26 that are substantially the same as the inner housing 124 of the second embodiment. The rod-shaped member 212 has a circular cross section and is made of stainless steel. The plurality of rod-like members 212 are positioned so as to cross the gap G without substantially extending into the scroll chamber S2. Although not clearly shown in FIG. 14, the inner divided portion P4 and the outer divided portion P2 are provided with semicircular recesses 214 and 216 into which the rod-shaped member 212 is fitted, respectively. It is sandwiched between 216 and joined. Accordingly, although not shown, the outer end 212 a of the rod-like member 212 is recognized in the appearance of the turbine housing 210.

  In addition, the cross section of the rod-shaped member 212 is not limited to a circle, and may be a square, a rectangle, or a polygon. Further, although four rod-like members 212 are shown in FIG. 14, the number may be any number such as eight or twelve. However, it is desirable that the interval between the rod-like members 212 is equal.

  As mentioned above, although this invention was demonstrated based on said 1st to 3rd embodiment, this invention is not limited to them.

  For example, in the first embodiment, the shroud member 66 and the outer housing 26 are directly fixed to form the closed portion of the gap G2. However, various structures of the closed portion can be considered, for example, Another member (for example, the outlet pipe 64) may be interposed between the shroud member 66 and the outer housing 26, and these three members may be fixed together to form a closing portion. The turbine housing according to the present invention can also be applied to other turbine types such as a mixed flow turbine and a variable capacity turbine.

  In addition, between the inner housings 24, 124, and 224 and the outer housing 26, SUS mesh, ceramic wool, etc. are used in order to maintain a good gap G between them, maintain the shape of the inner housings 24, 124, and 224, and heat insulation. Filling members having excellent heat resistance, corrosion resistance, and flexibility may be disposed in whole or in part. When they are disposed, for example, they are fixed inside the outer housing 26. Is preferred.

  Although the present invention has been described with a certain degree of concreteness, various modifications and changes can be made to the present invention without departing from the spirit and scope of the invention described in the claims. Must be understood. That is, the present invention includes modifications and changes that fall within the scope and spirit of the appended claims and their equivalents.

It is a right view of the turbine housing which concerns on 1st embodiment. It is a left view of the turbine housing shown in FIG. It is a front view of the turbine housing shown in FIG. It is a rear view of the turbine housing shown in FIG. It is sectional drawing along the AA line of FIG. It is sectional drawing along the BB line of FIG. It is an expansion schematic diagram of the tongue part along the CC line of FIG. 5 which excluded the 1st run-up member and the 2nd run-up member. It is a figure which shows the place which piled up the plate-shaped member on sectional drawing of FIG. It is an external view of an entrance. It is an enlarged view of the E section of FIG. It is an enlarged view of the D section of FIG. It is a figure corresponding to the AA line section equivalent figure of Drawing 1 of the turbine housing concerning a second embodiment. FIG. 13 is a cross-sectional view of the turbine housing of FIG. 12 taken along line BB of FIG. 3. It is sectional drawing corresponding to FIG. 12 of the turbine housing of 3rd embodiment.

Explanation of symbols

10, 110, 210 Turbine housing 42 Plate-shaped member 112 Horseshoe-shaped member 212 Bar-shaped member

Claims (3)

In a turbine housing comprising an inner housing and an outer housing that covers the inner housing with a gap therebetween,
The inner housing has an inner divided portion at an axially intermediate portion of the scroll chamber,
The outer housing has an outer divided portion in an axially intermediate portion of the scroll chamber;
A connecting member that connects the inner housing and the outer housing at an intermediate portion in the axial direction of the scroll chamber while the gap is maintained is joined while being sandwiched between the inner divided portion and the outer divided portion. Turbine housing characterized.   The turbine housing according to claim 1, wherein the connecting member has a plate shape. 3. The turbine housing according to claim 2, wherein the connecting member extends inward of the inner housing, partitions the scroll chamber so as to be divided into two in the axial direction, and forms the scroll chamber in a twin scroll shape. .

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