JP2015025460A - Seal structure for turbocharger housing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal structure for a turbocharger housing, for enhancing the sealing performance of a joint between a turbine housing and a bearing housing, while saving the machining cost by simplifying the structure of the joint and allowing easy machining of the joint.SOLUTION: The end face of a turbine housing 12 consists of an inside end face 14b which contacts a flange part 32 of a bearing housing 30 to form a seal surface, and an outside end face 14a to which a head seat surface 44a of a bolt 40 is closely attached after the bolt is fastened. A elastically deformable seal ring 48 is mounted on the seal surface. A compression margin of the seal ring after elastically deformed is set according to a level difference between the head seat surface of the bolt and the outside end face, formed before the bolt is fastened. A heat-shielding wall 32c is provided on the back face of the flange part integrally with the flange part. Spaces equivalent to the compression margin are provided between a back face 32b of the flange part and the inside end face of the turbine housing and between the front end of the heat-shielding wall 32c and a nozzle mount 24 before the bolt is fastened, respectively.

Description

  The present invention relates to a seal structure for sealing a joint surface between a turbine housing and a bearing housing of a turbocharger.

  A joint portion between the turbine housing and the bearing housing of the turbocharger is joined with a bolt or the like. The joint surface of the joint portion needs to be sealed so that the exhaust gas flowing inside the turbine housing does not leak to the outside. Therefore, a seal ring having a semicircular cross section, a C-shaped cross section, a V-shaped cross section, or the like is interposed on the joint surface. These seal rings are gaskets that receive the gas pressure of the exhaust gas inside the ring and are pressed against the storage surface by this gas pressure to exhibit sealing performance.

  However, due to the addition of bolt fastening force, the seal ring may be plastically deformed, or the joint may be thermally expanded due to high-temperature exhaust gas flowing into the turbine housing, which may cause gaps in the joint. May occur and gas leakage may occur.

  Patent Document 1 discloses a sealing means in which a gasket is interposed at a joint portion between a turbine housing and a bearing housing. The structure of this sealing means will be described with reference to FIG. In FIG. 9, a turbine shaft 106 and a turbine blade 108 coupled to the turbine shaft 106 are disposed inside a turbine housing 102 and a bearing housing 104 that constitute the housing of the turbocharger 100. The turbine shaft 106 is connected to a compressor rotor blade (not shown). A bearing 110 that rotatably supports the turbine shaft 106 is provided in the bearing housing 104.

  The exhaust gas e that has flowed into the spiral scroll passage 112 formed inside the turbine housing 102 rotates the turbine rotor blade 108 and the turbine shaft 106. Further, the compressor blades connected to the turbine shaft 106 are rotated, and the engine is supplied with air by the rotation of the compressor blades. A heat shield plate 116 is interposed between the scroll flow path 112 and the bearing housing 104, and a heat insulating space 118 is formed on the bearing housing 104 side from the heat shield plate 116.

  The turbine housing 102 and the flange portion 114 formed integrally with the bearing housing 104 are joined by bolts 120, and a gasket 126 is interposed between the joining surface 122 of the turbine housing 102 and the joining surface 124 of the flange portion 114. ing. This gasket 124 ensures the sealing performance of the joint surfaces 122 and 124.

  Patent Document 2 discloses another configuration of the joint between the turbine housing and the bearing housing. Hereinafter, the structure of the joint will be described with reference to FIG. In the turbocharger 200 shown in FIG. 10, the turbine housing 202 includes a concave portion 204 into which a flange portion 212 formed around the bearing housing 210 is inserted. The flange portion 212 protrudes into the recess 204 and forms a step G between the flange portion 212 and the end surface 206 of the turbine housing 202.

  A hole 208 opened in the end surface 206 of the turbine housing 202 is formed, and a female screw portion 209 is formed in the hole 208. A bolt 220 is screwed into the female screw portion 209, and a washer 224 is interposed between the seat surface 222 of the fastening bolt head and the end surface 206 of the turbine housing 202. The washer 224 is disposed so as to incline across the step G. Here, the washer 224 is elastically deformed by the fastening force of the fastening bolt 220 to generate tension on the fastening bolt 220.

  Thus, the axial force of the bolt 220 is increased to prevent a decrease in the axial force during operation, and the turbine housing 202 and the bearing housing 204 can be tightened more firmly.

Japanese Laid-Open Patent Publication No. 7-189723 JP 2010-209708 A

Engine combustion gas temperature is increasing year by year to improve engine output. Therefore, the thermal expansion of the turbine housing and the bearing housing due to the exhaust gas has increased, and the risk of gas leakage from the joint portion of these housings has increased.
In the sealing means disclosed in Patent Document 1, since the turbocharger 100 is operated and thermal expansion of the turbine housing 102 and the bearing housing 104 and the like is not taken into consideration, a gap is generated at the joint during these thermal expansions. Gas leakage may occur.

  In the configuration of the joint portion disclosed in Patent Document 2, since a step G is formed between the flange portion 212 and the end surface 206 of the turbine housing 202, the end bolt 206 or the fastening bolt 220 is provided between the end surface 206 and the washer 224. A gap is formed between the seating surface 222 and the washer 224. Therefore, there exists a problem that the sealing performance of the junction part of a housing cannot be improved.

  In view of the problems of the prior art, the first object of the present invention is to improve the sealing performance of the joint portion between the turbine housing and the bearing housing, even with the recent trend of increasing exhaust gas temperature. It is a second object of the present invention to simplify the structure of the joint portion, to make the housing parts versatile and to expand the application, to facilitate the processing of the joint portion, and to reduce the processing cost.

To achieve this object, a seal structure for a turbocharger housing according to the present invention is a seal structure for sealing a joint surface between a turbine housing of a turbocharger and a bearing housing, and the end surface of the turbine housing is a flange portion of the bearing housing. An inner end surface that forms a seal surface in contact with the flange portion and an outer end surface that does not form the flange and the seal surface, and is formed with a step with the inner end surface, and the head seating surface of the bolt closely contacts after tightening the bolt,
An elastically deformable seal ring is interposed on the seal surface, and the flange portion is sandwiched between the head seat surface of the bolt screwed into the end surface of the turbine housing and the inner end surface to elastically deform the seal ring. The rear crushing allowance is configured to be set by a step between the head seating surface of the bolt and the outer end surface formed before fastening the bolt, and is formed integrally with the flange portion on the back surface of the flange portion, A heat shield wall is provided to shield between the interior space of the turbine housing and the seal ring, and between the rear surface of the flange portion and the inner end surface of the turbine housing and the heat shield wall before the bolt fastening. An interval corresponding to the crushing allowance is open between the tip portion and a nozzle mount that is provided inside the turbine housing and forms an exhaust gas flow path.

  As described above, since the flange portion of the bearing housing is sandwiched between the head seat surface of the bolt and the inner end surface of the turbine housing, the sealing performance of the joint surface is improved while allowing thermal deformation of the turbine housing and the bearing housing. Can be maintained.

  In addition, a step is provided between the bolt contact surface of the flange portion of the bearing housing and the outer end surface of the turbine housing, and after fastening with the bolt, the seal surface formed by the flange portion and the inner end surface of the turbine housing is interposed. Since the formed seal ring is pressed and elastically deformed by a crushing amount corresponding to the step, even if the seal ring is thermally deformed, the sealing performance of the seal surface can be maintained high while allowing the heat deformation.

  In addition, the crush margin after elastic deformation of the seal ring is set by the level difference between the flange portion formed before tightening with the bolt and the outer end surface of the turbine housing. Easy to set up.

Further, since the flange portion of the bearing housing is clamped between the head seat surface of the bolt and the inner end surface of the turbine housing, it is not necessary to provide a bolt hole or the like in the flange portion of the bearing housing. This facilitates processing of the flange portion of the bearing housing, and can reduce processing costs. Further, the versatility of the bearing housing is widened, and the application can be expanded.
In addition, since a heat shield wall is provided on the rear surface of the flange portion so as to be integrated with the flange portion and shields the space between the internal space of the turbine housing and the seal ring, the seal ring is prevented from being deteriorated by heat and sealed. The life of the ring can be extended.

Further, according to the present invention, an elastically deformable seal ring is interposed on the seal surface, and a step corresponding to a collapse allowance of the seal ring is provided between the flange portion of the bearing housing and the outer end surface of the turbine housing before the bolt is tightened. Is formed.
Thus, after tightening with the bolt, the seal ring can be pressed and elastically deformed by the crushing allowance, so that the sealing performance of the sealing surface can be maintained high even if the sealing surface constituting member is thermally deformed. Further, since only the seal ring is elastically deformed, it is not necessary to elastically deform the turbine housing or the bearing housing. Therefore, the freedom degree of selection of the material of a turbine housing or a bearing housing can be expanded.

Further, the present invention provides an exhaust gas flow path provided between the rear surface of the flange portion and the inner end surface of the turbine housing, and at the front end portion of the heat shield wall and the inside of the turbine housing before the bolt fastening. An interval corresponding to the crushing allowance is opened between the nozzle mount and the nozzle mount.
Furthermore, the head seating surface of the bolt is brought into close contact with the outer end surface after the bolt is tightened, so that the space between the rear surface of the flange portion and the inner end surface of the turbine housing, and the front end portion of the heat shield wall and the The distance between the nozzle mount is closed. As a result, the seal ring is elastically deformed by the crushing allowance. Thus, the sealing performance of the sealing surface can be further improved by the heat shield plate.

  Further, in the seal structure of the present invention, the seal ring has an approximately semicircular cross-sectional shape, and both ends of the seal ring are pressed against the back surface and the inner end surface of the flange portion, respectively, after the bolt is fastened. Features. Thus, the seal ring is configured to be elastically deformable.

The turbocharger housing seal structure as a reference invention is a seal structure for sealing the joint surface between the turbine housing and the bearing housing of the turbocharger, and the end surface of the turbine housing is in contact with the flange portion of the bearing housing and sealed. An inner end surface that forms a surface and an outer end surface that forms a step with the inner end surface and does not form a sealing surface with the flange portion, and the head seating surface of the bolt closely contacts after tightening the bolt. The component member is constituted only by the flange portion of the bearing housing that can be elastically deformed and the inner end surface of the turbine housing, and the flange is formed by the head seat surface of the bolt screwed into the end surface of the turbine housing and the inner end surface. Sandwiching the portion, the flange portion of the bearing housing and the Over crushed margin after elastic deformation of the inner end surface of the bottle housing is obtained so as to be set by the difference in level between the head seating surface of the bolt is formed before bolting to the outer end surface.
This eliminates the need for a special seal member such as a seal ring and simplifies the seal structure.

  In the seal structure of the reference invention, the flange portion of the bearing housing may be constituted by a leaf spring, and a step corresponding to the collapse allowance of the leaf spring may be formed between the leaf spring and the outer end surface of the turbine housing. . As a result, due to the elastic deformation of the leaf spring, the sealing performance of the joint can be ensured, a special seal member such as a seal ring is not required, and the seal structure can be simplified.

In the seal structure of the reference invention, it is preferable that the inner end surface of the turbine housing and the facing surface of the flange portion of the bearing housing are processed into a tapered surface, and the tapered surface forming portion is formed of an elastically deformable member.
As a result, the thermal deformation of the sealing surface constituent member can be absorbed by relative sliding between the two tapered surfaces, so that the sealing performance of the sealing surface can be maintained high regardless of the thermal deformation of the sealing surface constituent member. Further, the configuration of the sealing surface can be simplified, and a special sealing member is not necessary.

In the seal structure of the reference invention, a tapered protrusion is formed on at least one of the joint surface of the flange portion of the bearing housing or the inner end surface of the turbine housing, and the protrusion is in line contact with the other joint surface. A step corresponding to the crushing margin of the protrusion may be formed between the outer end surface of the housing.
Accordingly, a large linear pressure can be generated between the protrusion and the facing surface by the tightening force of the bolt. Therefore, the sealing performance of the sealing surface can be maintained high even against thermal deformation of the sealing surface constituent member. Therefore, a special seal member is not required, and the seal structure can be simplified.

  In the seal structure of the reference invention, the joint surface of the flange portion of the bearing housing and the inner end surface of the turbine housing may be formed in a labyrinth structure, and the labyrinth structure forming portion may be formed of an elastically deformable member.

  As described above, since the labyrinth structure is formed on the seal surface, the sealing performance can be maintained high even if the seal surface constituent member is thermally deformed due to the gas pressure reduction effect of the labyrinth structure. Moreover, since a special seal member is not required, the seal structure can be simplified.

  In the seal structure of the reference invention and the present invention, it is preferable that the head portion of the bolt is provided with a flange or a washer that is in contact with the flange portion of the bearing housing and expands a contact surface with the flange portion. Thereby, the contact area between the seat surface of the bolt and the flange portion can be increased, the fastening force of the bolt to the flange portion can be increased, and the flange portion can be clamped more firmly.

  According to the present invention, in a seal structure for sealing a joint surface between a turbine housing of a turbocharger and a bearing housing, an inner end surface in which an end surface of the turbine housing is in contact with a flange portion of the bearing housing to form a seal surface; A seal ring that does not form a flange and a seal surface, and is composed of an inner end surface of the turbine housing and an outer end surface having a step with respect to the bolt contact surface of the flange portion. The flange portion is sandwiched between the head seating surface of the bolt screwed into the end surface of the turbine housing and the inner end surface of the turbine housing. It is set by the level difference between the bolt contact surface of the flange portion to be formed and the outer end surface of the turbine housing. Because it was Unishi, sealing performance of the joint surfaces while allowing thermal deformation of the turbine housing and the bearing housing can be kept high.

  In addition, it is easy to set a crushing allowance that can exert the best sealing performance, and it becomes easy to process the flange portion of the bearing housing, so that the processing cost can be reduced and the versatility of the bearing housing can be expanded.

It is sectional drawing of the turbocharger housing which concerns on 1st Embodiment of this invention apparatus. It is a perspective view of the turbocharger housing which concerns on the 1st reference form of this invention apparatus. It is a partial expanded sectional view of the said 1st reference form. It is a partially expanded sectional view of the turbocharger housing which concerns on the 2nd reference form of this invention apparatus. It is a partial expanded sectional view of the turbocharger housing which concerns on the 3rd reference form of this invention apparatus. It is a partially expanded sectional view of the turbocharger housing which concerns on the 4th reference form of this invention apparatus. It is a partially expanded sectional view of the turbocharger housing which concerns on the 5th reference form of this invention apparatus. It is a partially expanded sectional view of the turbocharger housing which concerns on the 6th reference form of this invention apparatus. It is sectional drawing of the conventional turbocharger housing. It is a partially expanded sectional view which shows another structure of the conventional turbocharger housing.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.

(Embodiment 1)
1st Embodiment of this invention apparatus is described based on FIG. In the turbocharger 10 shown in FIG. 1, the joint portion 14 of the turbine housing 12 and the flange portion 32 of the bearing housing 30 are coupled by a flange bolt 40. A spiral scroll passage 18 into which the exhaust gas e flows is formed in the turbine housing 12 by the nozzle plate 22 and the nozzle mount 24.

  A turbine shaft 28 is disposed on the central axis C of the turbine housing 12, and a plurality of turbine blades 26 are integrally formed on the turbine shaft 28. The exhaust gas e flowing into the turbine rotor blade side from the scroll passage 18 rotates through the outlet passage 20 after rotating the turbine rotor blade 26 and the turbine shaft 28.

  The bearing housing 30 is provided with a bearing 34 that rotatably supports the turbine shaft 28, and a lubricating oil passage 36 that supplies lubricating oil to the bearing 34. A plurality of bolt holes 16 are provided in the joint portion 14 of the turbine housing 12 in the circumferential direction of the turbine housing 12. In the flange bolt 40, a disk-shaped flange 44 is integrally formed on the lower surface of a hexagonal bolt head 42, the male screw portion 46 is screwed into the bolt hole 16, and the lower surface of the flange 44 is the flange of the bearing housing 30. The turbine housing 12 and the bearing housing 30 are coupled by pressing the portion 32.

  An annular space s having a square cross section is formed between the inner end surface 14b of the turbine housing 12 and the back surface 32b of the flange portion 32, and a seal ring 48 is interposed in the annular space s. The seal ring 48 has an approximately semicircular cross section and is configured to be elastically deformable. FIG. 1 shows a state before the flange bolt 40 is tightened. In this state, the seal ring 48 is not yet elastically deformed, and only corresponds to the crushing amount h of the seal ring 48 between the bolt contact surface 32a of the flange portion 32 and the outer end surface 14a of the turbine housing 12. A step G is formed.

  In addition, the gap between the back surface 32 b of the flange portion 32 and the inner end surface 14 b of the turbine housing 12 and the space between the heat shield wall 32 c integrated with the flange portion 32 and the nozzle mount 24 are equivalent to the collapse allowance h of the seal ring 48. is open. In this state, the flange bolt 40 is screwed into the bolt hole 16 and the seating surface 44a of the flange 44 is brought into close contact with the outer end surface 14a. Elastically deforms. In this state, the flange portion 32 is sandwiched between the flange 44 and the inner end surface 14 b of the turbine housing 12. Further, both ends of the seal ring 48 are in pressure contact with the back surface 32b and the inner end surface 14b of the flange portion 32, respectively.

  According to the present embodiment, the flange portion 32 is sandwiched between the inner surface of the seat surface 44a of the flange 44 and the inner end surface 14b of the turbine housing 12, so that thermal deformation of the joint portion 14 and the flange portion 32 is allowed. The sealing performance of the sealing surface formed between the seating surface 44a of the flange 44 and the bolt contact surface 32a and the outer end surface 14a of the flange portion 32 and between the back surface 32b of the flange portion 32 and the inner end surface 14b can be maintained high.

Further, a step G is provided between the bolt contact surface 32a of the flange portion 32 and the outer end surface 14a, and after tightening with the flange bolt 40, the seal ring 48 is pressed by a crushing amount h corresponding to the step G to be elastically deformed. Therefore, even if thermal deformation occurs around the seal ring 48, the sealing performance of the sealing surface can be maintained high while allowing this thermal deformation.
Further, since the crushing amount h after the elastic deformation of the seal ring 48 is set by the step G formed before tightening with the flange bolt 40, the setting of the crushing amount h of the seal ring 48 that can maximize the sealing performance. Becomes easier.

Further, since the flange portion 32 is sandwiched between the seat surface 44a and the inner end surface 14b of the flange 44, it is not necessary to provide a bolt hole or the like in the flange portion 32. As a result, the processing of the flange portion 32 is facilitated, and the processing cost can be reduced. Further, the versatility of the bearing housing is widened, and the application can be expanded.
Furthermore, in this embodiment, since the heat shield wall 32c that shields between the internal space of the housing and the seal ring 48 is provided, thermal deterioration of the seal ring 48 can be prevented and the life of the seal ring 48 can be extended. Moreover, the sealing performance of the sealing surface can be further improved by the heat shield wall 32c.

  In the present embodiment, the flange bolt 40 in which the bolt head 42 and the flange 44 are integrated is used. However, a bolt in which a flange or a washer is formed separately from the bolt head may be used.

(First reference form)
Next, a first reference embodiment of the device of the present invention will be described with reference to FIGS. As shown in FIG. 2, the housing of the turbocharger 50 </ b> A according to the present embodiment includes a turbine housing 52, a bearing housing 54, and a compressor housing 56. A plurality of joints 60 are formed in the circumferential direction of the turbine housing 52, and as shown in FIG. 3, bolt holes 62 opened in the outer end surface 60 a are formed in the joints 60.

As shown in FIG. 3, a bolt 64 with a collar is screwed into the bolt hole 62. The flanged bolt 64 is integrally formed with a hexagonal bolt head 66 with a disk-shaped collar 68 having a diameter larger than that of the bolt head. A step is formed between the outer end surface 60 a and the inner end surface 60 b of the turbine housing 52. A flange portion 70 is integrally formed with the bearing housing 54. A seal ring 72 having a C-shaped cross section and elastically deformable is interposed between the flange portion 70 and the inner end surface 60b.

  FIG. 3 shows a state before tightening with the flanged bolt 64. Before tightening, the outer end surface 60a and the bolt contact surface 70a of the flange portion 70 have a step G. The step G is set to be the same as the crushing margin of the seal ring 72. The step G is eliminated by screwing the flanged bolt 64 to the outer end surface 60a and bringing the collar 68 into close contact with the outer end surface 60a. At the same time, the seal ring 72 is pressed by the back surface 70b and the inner end surface 14b of the flange portion 70, and is elastically deformed by the set amount of crushing.

According to the present embodiment, since the seal ring 72 is elastically deformed, even if the flange portion 70 and the joint portion 60 are thermally deformed by the heat of the exhaust gas passing through the exhaust gas flow path 74, the bolts of the flange portion 70. The sealing performance of the sealing surface constituted by the contact surface 70a and the back surface 70b and the outer end surface 60a and the inner end surface 14b of the turbine housing 52 can be maintained high.
Further, since the bolt hole or the like of the flange portion 70 is not provided, the shape of the flange portion 70 can be simplified, the application of the bearing housing 54 can be expanded, and the crushing margin of the seal ring 72 is set to be the same as the step G. This facilitates the setting of the optimum crushing allowance for the sealing performance of the seal ring 72.

(Second reference form)
Next, a second reference embodiment of the device of the present invention will be described with reference to FIG. In the turbocharger 50B of the present embodiment, a heat shield wall 76 is integrally formed on the inner end surface 60b between the exhaust gas passage 74 and the seal ring 72. The distance h between the heat shield wall 76 and the back surface 70 b of the flange portion 70 is set to be the same as the crushing allowance set for the step G and the seal ring 72. Other configurations are the same as those of the first reference embodiment.

  In this configuration, when the collar 68 of the collard bolt 64 is screwed in until it comes into close contact with the outer end surface 60a, the heat shield wall 76 and the back surface 70b of the flange portion 70 are in close contact with each other, and the crush margin in which the seal ring 72 is set Only elastically deforms. Therefore, the same operational effects as those of the first reference embodiment can be obtained, and the heat shielding wall 76 can prevent the exhaust gas from entering the seal ring 72. Therefore, thermal deterioration of the seal ring 72 can be prevented, the life of the seal ring 72 can be extended, and the sealing performance of the seal surface can be further enhanced by the arrangement of the heat shield wall 76.

(3rd reference form)
Next, a third reference embodiment of the device of the present invention will be described with reference to FIG. In the turbocharger 50C according to the present embodiment, the bolt head portion 82 and the male screw portion 84 of the bolt 80 and the washer 86 are configured separately. The flange portion 70 of the bearing housing 54 is configured by a leaf spring. A step is formed between the outer end surface 60 a and the inner end surface 60 b of the turbine housing 52. Before the bolt 80 is tightened, a step G is formed between the flange portion 70 and the outer end surface 60a.

  When the bolt 80 is screwed into the bolt hole 62 and the washer 86 is brought into close contact with the outer end surface 60a, the flange portion 70 is pushed by the washer 86 to be elastically deformed and comes into contact with the inner end surface 60b. The inner end surface 60 b is formed in a curved surface in accordance with the back surface shape after the elastic deformation of the flange portion 70.

  In the present embodiment, since the back surface 70a of the flange portion 70 is in close contact with the inner end surface 60b, the sealing performance of the sealing surface can be maintained high even if the sealing surface constituent member is deformed by the heat of the exhaust gas. Moreover, since the flange part 70 is comprised with the leaf | plate spring, it is elastic, can form a sealing surface easily, has good heat resistance, and can extend life even under the high temperature of exhaust gas.

(4th reference form)
Next, a fourth reference embodiment of the device of the present invention will be described with reference to FIG. In the turbocharger 50D of the present embodiment, the inner end surface 60b of the turbine housing 52 is formed with a flat tapered surface, and the front end portion of the rear surface 70b of the flange portion 70 facing the inner end surface 60b is flat at the same angle as the inner end surface 60b. The tapered surface 90 is formed. The inner end surface 60b and the tapered surface 90 of the flange portion 70 have the same inclination angle so as to be in contact with each other. Moreover, the taper surface formation site | part of the flange part 70 and the junction part 60 is comprised with the elastic material. Other configurations are the same as those of the third reference embodiment.

  In such a configuration, the outer end surface 60a and the bolt contact surface 70a of the flange portion 70 have a step G before the bolt 80 is tightened. When the bolt 80 is screwed in until the washer 86 is in close contact with the outer end surface 60a, the inner end surface 60b and the tapered surface 90 are in close contact with each other, and the tapered surface forming portion is elastically deformed and pressed against each other. The bolt contact surface 70a and the outer end surface 60a of the 70 are the same height.

  According to this reference embodiment, even if the flange portion 70 and the joint portion 60 are thermally deformed with a simple configuration in which the inner end surface 60b and the front end portion of the back surface 70b of the flange portion 70 are merely the tapered surface 90, the sealing surface High sealing performance can be maintained.

(5th reference form)
Next, a fifth reference embodiment of the device of the present invention will be described with reference to FIG. In the turbocharger 50E of this reference embodiment, a protrusion 92 having a tapered cross section and a wedge shape is provided at the tip of the back surface 70b of the flange portion 70. Before the bolt 80 is tightened, the bolt contact surface 70a and the outer end surface 60a of the flange portion 70 are configured to form a step G when the tip of the projection 92 contacts the inner end surface 60b. Other configurations are the same as those in the fourth embodiment.

In this configuration, when the bolt 80 is screwed in until the washer 86 is in close contact with the outer end surface 60a, the tip of the projection 92 is pressed against the inner end surface 60b, and the tip is pressed against the inner end surface 60b while being elastically deformed. It becomes a state. Therefore, even if the flange portion 70 and the joint portion 60 are deformed by the heat of the exhaust gas passing through the exhaust gas passage 74, the sealing performance of the seal surface can be maintained high. Further, a simple configuration in which the protrusion 92 is provided on the back surface 70b of the flange portion 70 can be obtained.

(6th reference form)
Next, a sixth reference embodiment of the device of the present invention will be described with reference to FIG. The turbocharger 50F according to the present embodiment is formed by forming a labyrinth structure 94 on the back surface 70b of the flange portion 70 and the inner end surface 60b of the turbine housing 52. Other configurations are the same as those of the fifth reference embodiment. FIG. 8 shows a state before the bolt 80 is tightened, and a step G is formed between the bolt contact surface 70a of the flange portion 70 and the outer end surface 60a. Further, at the left and right ends of the labyrinth structure 94, gaps A and B having the same dimensions as the step G are formed.

  In such a configuration, when the bolt 80 is screwed into the bolt hole 62 until the washer 86 is in close contact with the outer end surface 60a, the step G between the bolt contact surface 70a and the outer end surface 60a of the flange portion 70 is eliminated. At the same time, the spaces A and B are also closed, and both ends of the labyrinth structure 94 are sealed.

  According to the present embodiment, after the bolt 80 is tightened, the spaces A and B are sealed, and the labyrinth structure 94 is formed between the spaces A and B, so that the flange portion 70 and the joint portion 60 are thermally deformed. Nevertheless, the sealing performance of the sealing surface can be maintained well.

  ADVANTAGE OF THE INVENTION According to this invention, the turbocharger housing which can improve the sealing performance of a housing joint surface with a simple structure also with respect to the thermal deformation which a housing part receives is realizable.

10, 50A, 50B, 50C, 50D, 50E, 50F Turbocharger 12, 52 Turbine housing 14, 60 Joint 14a, 60a Outer end face 14b, 60b Inner end face 16, 62 Bolt hole 18 Scroll passage 20 Outlet passage 22 Nozzle Plate 24 Nozzle mount 26 Turbine blade 30, 54 Bearing housing 32, 70 Flange part 32a, 70a Bolt contact surface 32b, 70b Rear surface 32c, 76 Heat shield wall 34 Bearing 36 Lubricating oil flow path 40 Flange bolt 42, 66, 82 Bolt head 44 Flange 44a Seat surface 46, 84 Male thread 48, 72 Seal ring 56 Compressor housing 64 Collar bolt 68 Collar 74 Exhaust gas flow path 80 Bolt 86 Washer 90 Tapered surface 92 Protrusion 94 Labyrinth structure C central axis G step e exhaust gas h crushing allowance s annular space

Claims (4)

In the sealing structure for sealing the joint surface between the turbine housing and the bearing housing of the turbocharger,
The end surface of the turbine housing is formed with an inner end surface that forms a seal surface in contact with the flange portion of the bearing housing and a step with the inner end surface that does not form a seal surface with the flange portion. It consists of the outer end face where the seating surface is in close contact,
An elastically deformable seal ring is interposed on the seal surface, and the flange portion is sandwiched between the head seat surface of the bolt screwed into the end surface of the turbine housing and the inner end surface,
The crushing allowance after elastic deformation of the seal ring is configured to be set by a step between the head seating surface of the bolt and the outer end surface formed before bolt fastening,
A heat insulating wall that is formed integrally with the flange portion on the back surface of the flange portion and shields between the internal space of the turbine housing and the seal ring;
Between the rear surface of the flange portion and the inner end surface of the turbine housing before fastening the bolt, and between the tip portion of the heat shield wall and a nozzle mount that is provided inside the turbine housing and forms an exhaust gas flow path. Is a seal structure for a turbocharger housing, wherein an interval corresponding to the crushing allowance is open.   After the bolts are fastened, the head seating surface of the bolts is brought into close contact with the outer end surface, so that the space between the rear surface of the flange portion and the inner end surface of the turbine housing, the front end portion of the heat shield wall, and the nozzle mount. 2. The turbocharger housing sealing structure according to claim 1, wherein a space between the first and second gas turbines is closed.   3. The seal ring according to claim 1, wherein the seal ring has an approximately semicircular cross-sectional shape, and both ends of the seal ring are pressed against the back surface and the inner end surface of the flange portion after the bolt is fastened, respectively. The turbocharger housing seal structure described.   The head part of the said bolt is provided with the flange or washer which contacts the flange part of a bearing housing, and expands a contact surface with this flange part integrally or separately. The turbocharger housing seal structure according to claim 1.

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