JP6325479B2 - Turbocharger - Google Patents

Description

  The present invention relates to a turbocharger, and more particularly to a turbocharger capable of changing a gas flow rate to a turbine wheel.

  Conventionally, in order to prevent the exhaust gas in the scroll passage from leaking into the turbine chamber, a turbocharger having a sealing device composed of a disc spring has been proposed (for example, JP 2009-144545 A (Patent Document 1). )reference).

JP 2009-144545 A

  The turbocharger blows the exhaust gas in the scroll passage to the turbine wheel to drive the turbine wheel to rotate. Hot exhaust gas exists in the scroll passage. In the configuration described in Patent Document 1, the disc spring is exposed in the scroll passage, and the disc spring is exposed to high-temperature exhaust gas. When the temperature of the disc spring increases, there is a problem in that the spring property of the disc spring decreases.

  The objective of this invention is providing the turbocharger which can suppress the heat damage of the disc spring by hot exhaust gas.

  A turbocharger according to the present invention includes a turbine wheel, a plurality of variable nozzles, a first plate, a second plate, a disc spring, and a shielding member. The variable nozzle is provided so as to be rotatable about a rotation shaft, and adjusts the flow rate of the exhaust gas to the turbine wheel. The 1st plate and the 2nd plate are arranged on both sides of the variable nozzle in the direction in which the rotation axis extends. The first plate and the second plate are formed in an annular shape around the axis of the turbine wheel. The disc spring is provided on the surface of the second plate that does not face the variable nozzle. The disc spring biases the second plate. The shielding member shields the disc spring from the exhaust gas. The shielding member is configured separately from the second plate.

  Preferably, in the turbocharger, the shielding member is disposed with a disc spring interposed between the shielding plate and the second plate in a direction in which the rotation shaft extends.

  Preferably, in the turbocharger, the disc spring is in contact with the second plate to form an annular first seal portion, and in contact with the shielding member, the annular second seal having a smaller diameter than the first seal portion. Forming part.

  In the turbocharger, preferably, the shielding member covers the outer peripheral surface of the second plate.

  In the turbocharger, preferably, a spacer for forming a space for accommodating the variable nozzle is formed integrally with the first plate.

  In the turbocharger, preferably, the first plate is provided with an engaging portion that engages with the shielding member.

  According to the turbocharger of the present invention, the heat damage of the disc spring can be suppressed by shielding the disc spring from the high-temperature exhaust gas.

It is a fragmentary sectional view showing a schematic structure of a turbocharger of this embodiment. It is a side view of the variable nozzle mechanism seen from the left side of FIG. It is a side view of the variable nozzle mechanism seen from the right side of FIG. It is a fragmentary sectional view which expands and shows the variable nozzle mechanism and its peripheral part in FIG. FIG. 5 is an enlarged partial cross-sectional view of the variable nozzle mechanism and its peripheral portion in FIG. It is a schematic diagram explaining the assembly | attachment condition of a shielding member.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a partial cross-sectional view showing a schematic configuration of a turbocharger 10 of the present embodiment. In the present embodiment, the turbocharger 10 is mounted on a vehicle. This vehicle is equipped with an engine. The engine burns an air-fuel mixture of air sucked into the combustion chamber through the intake passage and fuel supplied to the combustion chamber. The engine is provided with a turbocharger 10 shown in FIG.

  The turbocharger 10 includes a turbine shaft 11 and a bearing housing 12. The bearing housing 12 accommodates the bearing 13. The turbine shaft 11 is rotatably supported by the bearing housing 12 by a bearing 13.

  The turbocharger 10 includes a turbine housing 14 and a compressor housing (not shown). The turbine housing 14 is disposed adjacent to one side (the right side in FIG. 1) of the bearing housing 12 in the direction along the axis L1 of the turbine shaft 11 (the left-right direction in FIG. 1; hereinafter referred to as the “axial direction”). Yes. The compressor housing composed of a plurality of members is disposed adjacent to the other side (left side in FIG. 1) of the bearing housing 12 in the axial direction.

  The turbine housing 14 and the compressor housing are respectively fastened and fixed to the bearing housing 12. The bearing housing 12, the turbine housing 14 and the compressor housing constitute a housing for the turbocharger 10.

  A cylindrical turbine chamber 15 extending in the axial direction is formed at the center of the turbine housing 14. A spiral scroll passage 16 is formed around the turbine chamber 15 in the turbine housing 14. The scroll passage 16 is formed outside the turbine chamber 15 in the radial direction of the turbine shaft 11. The turbine chamber 15 and the scroll passage 16 are in communication with each other via a communication passage 17 (see FIG. 4). The scroll passage 16 has an L-shaped cross section.

  A turbine wheel 26 that rotates in the turbine chamber 15 is fixed on one end (right side in FIG. 1) of the turbine shaft 11. A compressor wheel (not shown) that rotates in the compressor housing is fixed on the other end (left side in FIG. 1) of the turbine shaft 11.

  The turbine housing 14 is integrally formed with a bulging portion 18 extending toward the bearing housing 12. The bulging portion 18 has an annular shape centered on the axis L <b> 1 and constitutes a part of the inner wall surface of the turbine chamber 15.

  A variable nozzle mechanism (variable nozzle mechanism) 30 is incorporated in the turbocharger 10. The variable nozzle mechanism 30 changes the exhaust flow area of the communication passage 17 and makes the flow rate of the exhaust E sprayed to the turbine wheel 26 variable, thereby adjusting the rotational speed of the turbocharger 10 and forcing it into the combustion chamber. It is a mechanism for adjusting the amount of air sent.

  Next, a schematic configuration of the variable nozzle mechanism 30 will be described. FIG. 2 is a side view of the variable nozzle mechanism 30 viewed from the left in FIG. FIG. 3 is a side view of the variable nozzle mechanism 30 viewed from the right side of FIG. FIG. 2 shows a state in which a part of the variable nozzle mechanism 30 (nozzle plate 31 and the like) is viewed from the left side of FIG. FIG. 3 shows a state in which a part of the variable nozzle mechanism 30 (nozzle plate 31 and the like) is viewed from the right side of FIG.

  As shown in FIGS. 1, 2, and 3, the variable nozzle mechanism 30 includes a nozzle plate 31 and a unison ring 35. The nozzle plate 31 and the unison ring 35 have an annular shape centered on the axis L1.

  In the nozzle plate 31, a plurality of shafts 32 are arranged at substantially equal angles on a circle centered on the axis L1. Each shaft 32 extends parallel to the axis L1 and is rotatably inserted into the nozzle plate 31. Each shaft 32 extends along the axial direction. For each shaft 32, a variable nozzle (nozzle vane) 33 is fixed to one portion (right side in FIG. 1) exposed from the nozzle plate 31. In FIG. 1, the variable nozzle 33 is illustrated by a two-dot chain line. For each shaft 32, the base end portion of the arm 34 is fixed to the other end portion (left side in FIG. 1) exposed from the nozzle plate 31.

  The unison ring 35 has concave portions 36 at a plurality of locations on the inner peripheral surface. The tip portions of the arms 34 are engaged with these recesses 36.

  The unison ring 35 is rotated from the outside of the turbocharger 10 via a link 37 (see FIG. 1). In other words, the arm 39 is fixed to the shaft 37 </ b> A of the link 37, and the tip of the arm 39 is engaged with the recess 40 provided on the inner peripheral surface of the unison ring 35. When the unison ring 35 is rotated around the axis L1 from the outside of the turbocharger 10 via the link 37, the shaft 37A, the arm 39, etc., the unison ring 35 engages with the plurality of recesses 36 of the unison ring 35. Each arm 34 is rotated (opened and closed) in a state of being synchronized around the shaft 32.

  As each shaft 32 rotates, the variable nozzle 33 rotates about the shaft 32. The shaft 32 has a function as a rotation shaft. The opening of the variable nozzle 33 is changed by the rotation of the variable nozzle 33, and the exhaust flow area of the communication passage 17 is changed. And the flow velocity of the exhaust E sprayed on the turbine wheel 26 through between the adjacent variable nozzles 33 is adjusted.

  For example, in FIG. 2, when the arm 39 is rotated counterclockwise with the shaft 37A as a fulcrum by the link 37 or the like, the unison ring 35 is rotated in the directions indicated by the arrows in FIGS. . Due to the above-described rotation of the unison ring 35, each shaft 32 rotates counterclockwise in FIG. 2, and rotates clockwise in FIG. As the shafts 32 rotate, the variable nozzle 33 rotates toward the closing side, and the flow velocity of the exhaust E sprayed on the turbine wheel 26 increases. Contrary to the above, when the variable nozzle 33 rotates to the open side, the flow velocity of the exhaust E sprayed on the turbine wheel 26 decreases.

  FIG. 4 is an enlarged partial cross-sectional view showing the variable nozzle mechanism 30 and its peripheral portion in FIG. FIG. 5 is an enlarged partial cross-sectional view of the variable nozzle mechanism 30 in FIG. 1 and its peripheral portion, showing an enlarged cross section (cross section through a spacer portion 47 described later) different from that in FIGS.

  As shown in FIGS. 4 and 5, in the nozzle plate 31, through-holes penetrating in the axial direction are formed at a plurality of circular locations centering on the axis L <b> 1. The shaft 32 for each variable nozzle 33 is rotatably inserted into the through hole. The variable nozzle 33 is supported by the nozzle plate 31 so as to rotate integrally with the shaft 32.

  The variable nozzle mechanism 30 includes an annular shroud plate 41 centered on the axis L1. The nozzle plate 31 as the first plate and the shroud plate 41 as the second plate are arranged with a space therebetween in the direction in which the shaft 32 extends. The nozzle plate 31 and the shroud plate 41 are disposed with the variable nozzle 33 interposed therebetween. The shroud plate 41 is disposed on the side away from the bearing housing 12 with respect to the nozzle plate 31 (right sides in FIGS. 4 and 5). Each shaft 32 passes through the nozzle plate 31 and is supported by the nozzle plate 31 as described above, but is not inserted through the shroud plate 41.

  The shroud plate 41 has a first surface 42 facing the nozzle plate 31 and a second surface 43 opposite to the first surface 42. The first surface 42 faces the variable nozzle 33. The first surface 42 forms the inner wall of the communication path 17 together with the nozzle plate 31. One end of the shaft 32 is in contact with the first surface 42. The second surface is a surface opposite to the first surface 42 facing the variable nozzle 33. The second surface 43 faces the turbine housing 14. A part of the scroll passage 16 is formed between the second surface 43 and the inner wall surface of the turbine housing 14. The first surface 42 and the second surface 43 have portions formed substantially parallel to each other.

  The shroud plate 41 has a third surface 44, a fourth surface 45, and a fifth surface 46 at the outer peripheral edge portion thereof. The third surface 44, the fourth surface 45, and the fifth surface 46 are provided at the edge of the shroud plate 41 on the radially outer side. The fourth surface 45 is formed in an annular shape parallel to the first surface 42 and the second surface 43. The third surface 44 and the fifth surface 46 are formed in a cylindrical shape orthogonal to the first surface 42 and the second surface 43.

  The third surface 44 is formed closer to the axis L <b> 1 of the turbine shaft 11 than the fifth surface 46. The fourth surface 45 is formed between the first surface 42 and the second surface 43 in the axial direction. Thereby, the first surface 42, the third surface 44, the fourth surface 45, and the fifth surface 46 form a stepped shape at the outer peripheral edge portion of the shroud plate 41.

  As shown in FIG. 5, the nozzle plate 31 has a spacer portion 47. As shown in FIG. 3, the spacer portions 47 are provided at equal intervals (here, three) with a distance from each other in the circumferential direction of the nozzle plate 31. The spacer portion 47 extends from the nozzle plate 31 toward the shroud plate 41. The spacer portion 47 is formed integrally with the nozzle plate 31. The spacer portion 47 extends from the outer peripheral edge portion of the nozzle plate 31 along the axial direction. The spacer portion 47 is in contact with the first surface 42 of the shroud plate 41. The spacer 47 secures a space slightly larger than the thickness of the variable nozzle 33 between the nozzle plate 31 and the shroud plate 41.

  A part of the spacer portion 47 further extends to the side away from the bearing housing 12 to form a fitting portion 49. The fitting portion 49 is fitted into a stepped shape formed by the first surface 42, the third surface 44, the fourth surface 45, and the fifth surface 46 of the shroud plate 41. By this fitting, the nozzle plate 31 and the shroud plate 41 are connected to each other, and the nozzle plate 31 and the shroud plate 41 form an “assembly 48” integrally coupled to each other.

  In the assembly 48, a region sandwiched between the nozzle plate 31 and the shroud plate 41 is a region (operation region A) in which each variable nozzle 33 rotates (opens and closes) together with the shaft 32. The spacer portion 47 forms a space between the nozzle plate 31 and the shroud plate 41, and each variable nozzle 33 is accommodated in this space.

  A disc spring 50 is disposed on the second surface 43 of the shroud plate 41. The disc spring 50 is provided on the second surface 43 of the surface of the shroud plate 41 that does not face the variable nozzle 33. The disc spring 50 is formed in an annular shape by an elastic body such as a metal plate. The disc spring 50 is formed to be elastically deformable in the axial direction.

  The disc spring 50 is arranged around the axis L1. The disc spring 50 is disposed around the turbine wheel 26. The disc spring 50 is formed in a conical shape (tapered shape) that approaches the inner wall surface of the turbine housing 14 as it approaches the center.

  The disc spring 50 has a function of sealing a gap between the shroud plate 41 of the assembly 48 and the inner wall surface of the turbine housing 14. The disc spring 50 also has a function of urging the assembly 48 in the axial direction and pressing the assembly 48 against the inner wall surface of the bearing housing 12.

  Further, the turbocharger 10 includes a shielding member 60. The shielding member 60 is formed in an annular shape by an elastic body such as a metal plate. The shielding member 60 is disposed around the axis L1. The shielding member 60 is disposed around the turbine wheel 26. The shielding member 60 is configured separately from the shroud plate 41.

  A disc spring 50 is sandwiched between the shroud plate 41 and the shielding member 60 in the axial direction. The shielding member 60 surrounds the disc spring 50 together with the shroud plate 41. The shielding member 60 is disposed so as to cover the disc spring 50.

  The shielding member 60 has an inner peripheral edge 61 and an outer peripheral edge 62. Of the annular shield member 60 as a whole, the inner peripheral edge 61 constitutes a part of the surface of the innermost diameter portion. The outer peripheral edge 62 constitutes a part of the surface of the outermost diameter portion of the shielding member 60.

  The shielding member 60 includes an inner cylindrical portion 63, an annular portion 64, a tapered portion 65, an outer cylindrical portion 66, and an engaging convex portion 67. The inner cylindrical portion 63 has a cylindrical shape extending in the axial direction. An end portion of the inner cylindrical portion 63 facing the second surface 43 of the shroud plate 41 constitutes an inner peripheral edge 61 of the shielding member 60. The annular portion 64 has an annular shape extending in the radial direction of the turbine shaft 11. The annular portion 64 is disposed in contact with the inner wall surface of the bulging portion 18 of the turbine housing 14.

  The tapered portion 65 has a tapered surface shape whose diameter increases as it approaches the second surface 43 of the shroud plate 41. The outer cylindrical portion 66 has a cylindrical shape extending in the axial direction. The outer cylindrical portion 66 is disposed in contact with the fifth surface 46 of the shroud plate 41. The outer cylindrical portion 66 covers the fifth surface 46 of the shroud plate 41 from the radially outer side.

  The engagement convex portion 67 has an S-shape that is curved in a direction approaching the axis L1 from the outer cylindrical portion 66 and further curved in a direction away from the axis L1. The engaging convex part 67 is engaged with the outer peripheral surface of the fitting part 49 formed integrally with the nozzle plate 31. The engaging projection 67 covers the third surface 44 of the shroud plate 41 from the outside in the radial direction.

  The shielding member 60 is disposed between the scroll passage 16 and the disc spring 50. The shielding member 60 shields the disc spring 50 from high-temperature exhaust gas flowing in the scroll passage 16.

  The disc spring 50 is in contact with the annular portion 64 of the shielding member 60 at the inner peripheral edge portion to form an annular seal portion 51 centering on the axis L1. The disc spring 50 is in contact with the second surface 43 of the shroud plate 41 at the outer peripheral edge portion to form an annular seal portion 52 centering on the axis L1. The diameter of the seal part 51 is smaller than the diameter of the seal part 52.

  The disc spring 50 is bent (elastically deformed) in a direction in which the axial dimension is reduced by applying an axial load at the seal portions 51 and 52, and the assembly 48 is formed at the outer peripheral edge. (Shroud plate 41) is urged toward the bearing housing 12 side. By this urging, the nozzle plate 31 is pressed against the inner wall surface of the bearing housing 12.

  FIG. 6 is a schematic diagram for explaining the assembly state of the shielding member 60. As shown in FIG. 6, the spacer portion 47 has a contact surface 471 that contacts the first surface 42 of the shroud plate 41, an inner peripheral surface 472, and an outer peripheral surface 473. The contact surface 471 is formed in an annular shape. In a state where the nozzle plate 31 and the shroud plate 41 shown in FIG. 6 are assembled, the contact surface 471 is in surface contact with the first surface 42 of the shroud plate 41. The inner peripheral surface 472 is formed in an arc shape and faces the operation area A between the nozzle plate 31 and the shroud plate 41. The outer peripheral surface 473 is formed in an arc shape and faces the scroll passage 16.

  The fitting portion 49 has an inner peripheral surface 491, a facing surface 492, and an outer peripheral surface 493. The inner peripheral surface 491 is formed in an arc shape. The inner peripheral surface 491 is in surface contact with the third surface 44 of the shroud plate 41 in a state where the nozzle plate 31 and the shroud plate 41 shown in FIG. 6 are assembled. The facing surface 492 is formed in a partial annular shape. In the state where the nozzle plate 31 and the shroud plate 41 shown in FIG. 6 are assembled, the facing surface 492 is opposed to the fourth surface 45 with a gap between the facing surface 492 and the fourth surface 45 of the shroud plate 41. .

  The outer peripheral surface 493 is formed in an arc shape and faces the scroll passage 16. The outer peripheral surface 493 is provided with the same diameter and concentricity as the outer peripheral surface 473 of the spacer portion 47. The outer peripheral surface 493 is formed with an engaging recess 494 whose part is recessed. The bottom surface of the engaging recess 494 is disposed closer to the axis L1 than the outer peripheral surface 493. In the state where the nozzle plate 31 and the shroud plate 41 shown in FIG. 6 are assembled, the engaging recess 494 is provided within the range of the thickness of the shroud plate 41.

  In FIG. 6, the nozzle plate 31 and the shroud plate 41 are assembled, and the fitting portion 49 is fitted to the step portion of the outer peripheral edge portion of the shroud plate 41, and the disc spring 50 is attached to the second surface 43 of the shroud plate 41. A state in which is provided is shown. From this state, as shown by the arrow in FIG. 6, the shielding member 60 is moved to the left in FIG. 6 so as to approach the shroud plate 41. The engaging projection 67 of the shielding member 60 slides along the fifth surface 46 of the shroud plate 41 and further slides along the outer peripheral surface 493 of the fitting portion 49 to engage with the engaging recess 494. To do. In this way, the nozzle plate 31 and the shielding member 60 are combined, and the structure shown in FIG. 5 in which the disc spring 50 and the shielding member 60 are integrated with the assembly 48 is formed.

  The assembly of the shielding member 60 is not limited to the above example. For example, the shielding member 60 in a state where the bending of the outer cylindrical portion 66 with respect to the tapered portion 65 is smaller than that in FIG. 6 is arranged at a predetermined position, and the outer cylindrical portion 66 is bent by pressing or the like in this state. The engaging convex portion 67 may be engaged with the mating concave portion 494. As described above, when the shielding member 60 is arranged and then deformed and engaged with the nozzle plate 31, the engagement convex portion 67 is not limited to the S-shape, and for example, the outer peripheral edge of the shielding member 60 is bent. It is good also as a bowl shape.

  The operation of the turbocharger 10 of the present embodiment configured as described above will be described. As the engine operates, exhaust E is generated, and the exhaust E is exhausted from the engine. The exhaust E flows into the turbocharger 10 in the process of flowing through the exhaust passage, and flows along the scroll passage 16 of the turbine housing 14. The exhaust E passes through the communication path 17 between the adjacent variable nozzles 33 and is blown to the turbine wheel 26 in the turbine chamber 15.

  The turbine wheel 26 is rotationally driven by the blowing of the exhaust E. This rotation is transmitted to the compressor wheel via the turbine shaft 11. Thereby, the compressor wheel coaxial with the turbine wheel 26 rotates integrally with the turbine wheel 26. As a result, in the engine, the air sucked by the negative pressure generated in the combustion chamber as the piston moves is forced (supercharged) into the combustion chamber by the rotation of the compressor wheel of the turbocharger 10. In this way, the efficiency of filling the combustion chamber with air is increased.

  When the variable nozzle 33 is rotated from the outside of the turbocharger 10 through the operation of the link 37 or the like, the opening degree of the variable nozzle 33 is changed. Along with this, the flow rate of the exhaust E sprayed on the turbine wheel 26 is changed, the rotational speed of the turbocharger 10 is changed, and the supercharging pressure of the engine is adjusted.

  Here, in the turbocharger 10, the gap between the shroud plate 41 and the turbine housing 14 is sealed by the disc spring 50. In the turbocharger 10, the disc spring 50 is elastically deformed in the axial direction between the assembly 48 (the shroud plate 41) and the inner wall surface of the turbine housing 14, and is incorporated in a state where elastic energy is accumulated.

  The shroud plate 41 that is in contact with the seal portion 52 at the outer peripheral edge of the disc spring 50 is always urged in the axial direction by the force (elastic restoring force, urging force) of releasing the elastic energy of the disc spring 50. The The biasing force of the disc spring 50 is transmitted to the nozzle plate 31 via the spacer portion 47. By transmitting this urging force, the assembly 48 is displaced toward the bearing housing 12, and a part of the nozzle plate 31 is pressed against the inner wall surface of the bearing housing 12. By this pressing, the assembly 48 is positioned in a floating state without being fixed to the housings 12 and 14.

  Further, in the disc spring 50, the seal portion 52 at the outer peripheral portion contacts the shroud plate 41, and the seal portion 51 at the inner peripheral portion contacts the annular portion 64 of the shielding member 60. Due to the urging force of the disc spring 50, the annular portion 64 of the shielding member 60 contacts the inner wall surface of the turbine housing 14. In this way, the gap between the shroud plate 41 and the turbine housing 14 is partitioned by the disc spring 50 and the shielding member 60. Therefore, the flow of the exhaust E passing through the gap between the shroud plate 41 and the turbine housing 14 is restricted, and the exhaust E is prevented from leaking out to the turbine chamber 15 by bypassing the communication path 17.

  As shown in FIG. 5, the turbocharger 10 includes a shielding member 60 that shields the disc spring 50 from the exhaust E. Since the shield member 60 shields the disc spring 50 from the high-temperature exhaust E, the heat damage of the disc spring 50 can be suppressed, and the spring property of the disc spring 50 can be maintained. Thereby, the sealing performance by the disc spring 50 between the shroud plate 41 and the turbine housing 14 is securable. Further, the assembly 48 including the nozzle plate 31 and the shroud plate 41 can be pressed against the bearing housing 12 to stably fix the assembly 48.

  A space is formed between the tapered portion 65 of the shielding member 60 and the inner wall surface of the turbine housing 14, and this space constitutes a part of the scroll passage 16. The scroll passage 16 is formed close to the axis L1, and the scroll passage 16 is reduced in diameter. Therefore, the inner wall surface on the radially outer side of the scroll passage 16 can be disposed at a position closer to the axis L1 while securing the volume of the scroll passage 16, and the turbine housing 14 can be downsized.

  By configuring the shielding member 60 separately from the shroud plate 41, the disc spring 50 can be shielded from the exhaust E flowing through the scroll passage 16 having a reduced diameter with a simple configuration. In a state where the disc spring 50 is arranged on the second surface 43 of the shroud plate 41, the shielding member 60 is arranged so as to cover the disc spring 50, and the disc spring 50 is fixed by the shielding member 60 and the shroud plate 41, The disc spring 50 and the shielding member 60 can be easily assembled.

  In the turbocharger 10, each shaft 32 extends in the axial direction as shown in FIG. 1, and the shield member 60 has a disc spring 50 between the shroud plate 41 in the axial direction as shown in FIGS. 4 and 5. It is arranged on the other side. By arranging the shroud plate 41, the disc spring 50, and the shielding member 60 side by side in this order in the axial direction, a part of the scroll passage 16 is formed between the shielding member 60 and the turbine housing 14, and the inside of the scroll passage 16 A configuration for shielding the disc spring 50 from the exhaust E can be easily realized.

  In the turbocharger 10, as shown in FIGS. 4 and 5, the disc spring 50 is in contact with the second surface 43 of the shroud plate 41 to form an annular seal portion 52. An annular seal portion 51 having a diameter smaller than that of the seal portion 52 is formed in contact with the portion 64. A seal between the shroud plate 41 and the disc spring 50 is formed at the seal portion 52, a seal between the shielding member 60 and the disc spring 50 is formed at the seal portion 51, and the seal portion 51 further connects the annular portion 64 of the shielding member 60. It is pressed against the inner wall surface of the turbine housing 14. In this way, since the gap between the shroud plate 41 and the turbine housing 14 can be sealed, the flow of the exhaust E that bypasses the communication passage 17 can be reliably prevented.

  In the turbocharger 10, as shown in FIGS. 4 and 5, the shielding member 60 covers the third surface 44 and the fifth surface 46 constituting the outer peripheral surface of the shroud plate 41 from the radially outer side. Since the shielding member 60 has the outer cylindrical portion 66 and the engagement convex portion 67 extending so as to cover the outer peripheral surface of the shroud plate 41, the disc spring 50 can be more reliably shielded by the shielding member 60.

  In the turbocharger 10, as shown in FIG. 5, a spacer portion 47 is formed integrally with the nozzle plate 31. The spacer portion 47 forms a space for accommodating the variable nozzle 33 between the nozzle plate 31 and the shroud plate 41. Since the spacer portion 47 is formed integrally with the nozzle plate 31, it is not necessary to separately provide a spacer for forming a space for accommodating the variable nozzle 33, thereby reducing the number of parts and the nozzle plate 31 and the shroud. Assembling with the plate 41 can be facilitated.

  In the turbocharger 10, as shown in FIGS. 5 and 6, the engagement concave portion that engages with the engagement convex portion 67 of the shielding member 60 on the outer peripheral surface 493 of the fitting portion 49 formed integrally with the nozzle plate 31. 494 is formed. In this way, the cartridge structure in which the assembly 48 of the nozzle plate 31 and the shroud plate 41, the disc spring 50, and the shielding member 60 are integrated by engaging the shielding member 60 with the nozzle plate 31. It becomes possible to handle as. Thereby, the handling at the time of component replacement of the turbocharger 10 becomes easy, and the maintainability can be improved.

  At this time, the elements constituting the cartridge structure are not fixed together by joining means such as welding or caulking, but are positioned by pressing the elements against each other to generate an excessive restraining force. It is integrated in a floating state without any problems. Therefore, even if a temperature difference is generated between the nozzle plate 31 and the shroud plate 41, it is possible to avoid any element from being distorted by thermal stress. Therefore, deformation or damage of the cartridge structure can be prevented.

  In addition to the above configuration, for example, by engaging the engaging convex portion of the shielding member 60 with the engaging concave portion provided on the fifth surface of the shroud plate 41, the shroud plate 41, the disc spring 50, and the shielding member 60 are engaged. Can also be handled as an integrated cartridge structure. Even if it does in this way, while preventing the heat damage to the disc spring 50 by the exhaust_gas | exhaustion E, it bypasses the communicating path 17 and it is prevented that the exhaust_gas | exhaustion E leaks out to the turbine chamber 15. FIG.

  Although the embodiment of the present invention has been described as above, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 10 Turbocharger, 11 Turbine shaft, 12 Bearing housing, 14 Turbine housing, 15 Turbine chamber, 16 Scroll path, 17 Communication path, 18 Expansion part, 26 Turbine wheel, 30 Variable nozzle mechanism, 31 Nozzle plate, 32 Shaft, 33 Variable nozzle, 41 Shroud plate, 42 1st surface, 43 2nd surface, 44 3rd surface, 45 4th surface, 46 5th surface, 47 Spacer portion, 48 Assembly, 49 Fitting portion, 50 Belleville spring, 51 , 52 Sealing part, 60 Shielding member, 61 Inner peripheral edge, 62 Outer peripheral edge, 63 Inner cylindrical part, 64 Annular part, 65 Tapered part, 66 Outer cylindrical part, 67 Engaging convex part, 471 Contact surface, 472,491 Inner peripheral surface, 473,493 outer peripheral surface, 492 facing surface, 494 engaging recess, A working region, E exhaust, 1 axis.

Claims (5)

A turbine wheel,
A plurality of variable nozzles provided so as to be rotatable about a rotation axis and adjusting a flow rate of exhaust gas to the turbine wheel;
An annular first plate and a second plate centered on the axis of the turbine wheel, which are arranged across the variable nozzle in a direction in which the rotating shaft extends;
A disc spring provided on a surface of the second plate that does not face the variable nozzle and biases the second plate;
A shielding member configured to be separate from the second plate, which shields the disc spring from the exhaust gas ;
The disc spring is in contact with the second plate to form an annular first seal portion, and is in contact with the shielding member to form an annular second seal portion having a smaller diameter than the first seal portion. to that, the turbocharger.   2. The turbocharger according to claim 1, wherein the shielding member is disposed with the disc spring sandwiched between the shielding plate and the second plate in a direction in which the rotation shaft extends. The shielding member covers the outer peripheral surface of the second plate, turbocharger according to claim 1 or 2. The turbocharger according to any one of claims 1 to 3 , wherein a spacer for forming a space for accommodating the variable nozzle is formed integrally with the first plate. Wherein the first plate, the engaging portion engaging said shielding member is provided, the turbocharger according to any one of claims 1-4.

Images