JP2021165545A - Variable capacity type supercharger - Google Patents

Abstract

To provide a variable capacity type supercharger which can further improve assembling performance, in a heat shield positioning seal member in which three functions of the positioning of a variable nozzle unit to a housing, the suppression of a leak of an exhaust gas to the housing side from an intake side of a turbine wheel, and the suppression of the transmission of heat to the housing are aggregated.SOLUTION: In a variable capacity type supercharger having a turbine wheel, a housing, a variable nozzle and a nozzle plate, a housing tip external peripheral face opposes a plate internal peripheral face which is formed at an internal periphery of the nozzle plate at least partially in a direction along a rotation axial line, and a heat shield positioning seal member formed into a circular plate shape is arranged between a tip part of the housing and the turbine wheel. The heat shield positioning seal member has a circular ring-shaped inner-ring shaped protrusive curved part, a circular outer-ring shaped protrusive curved part, and a heat shield part extending to an internal peripheral side rather than the inner-ring shaped protrusive curved part, and covering at least a part of an end face of the tip part of the housing.SELECTED DRAWING: Figure 1

Description

The present invention relates to a variable displacement turbocharger.

The turbocharger of the internal combustion engine for a vehicle includes a variable capacity type supercharger capable of obtaining a high supercharging effect from a low rotation speed region to a high rotation speed region. A general variable capacity turbocharger includes a housing (bearing housing), a turbine wheel rotatably arranged in the housing, and a variable nozzle that changes the flow path area of exhaust gas supplied to the turbine wheel side. , Is equipped.

For example, in the variable displacement turbocharger 101 of Patent Document 1 shown in FIG. 4, the annular heat shield plate 130 that shields heat from the turbine impeller 105 side is the turbine impeller 105 (corresponding to the housing) of the bearing housing 120 (corresponding to the housing). It is fitted and provided on the side surface (corresponding to the turbine wheel). Further, a tapered fitting portion 131 capable of tapered fitting is formed at a position of the heat shield plate 130 facing the tapered fitting portion 135 on the radial side of the fitting portion 121.

In the variable displacement turbocharger 101, the tapered fitting portion 135 and the tapered fitting portion 131 come into contact with each other due to the difference in thermal expansion between the heat shield plate 130 and the bearing housing 120 at high temperature (during operation), and the tapered fitting portion 131 is fitted. A force is generated between the portion 135 and the taper fitting portion 131. The heat shield plate 130 is pushed toward the variable nozzle 111 by the component force of the generated force along the direction of the rotation axis JK2 of the turbine impeller 105, and the contact portion 133 of the heat shield plate 130 and a part of the nozzle ring 115. Can be sealed between and. As a result, leakage of exhaust gas from the variable nozzle 111 side to the bearing housing 120 is prevented, and a decrease in turbine efficiency is prevented.

Japanese Unexamined Patent Publication No. 2011-247189

In the variable displacement turbocharger 101 described in Patent Document 1, there is a gap between the tapered fitting portion 135 and the tapered fitting portion 131 due to the difference in thermal expansion at room temperature (during non-operation and warm-up operation). May occur, and it may not be possible to seal between the contact portion 133 and a part of the nozzle ring 115. Further, in the variable displacement turbocharger 101, the heat shield plate 130 contracts in the radial direction of the turbine impeller 105 at room temperature (during non-operation and warm-up operation), and the nozzle ring 115 and the heat shield plate 130 A gap may occur between the nozzle rings 115 so that the nozzle ring 115 cannot be positioned with respect to the bearing housing 120.

The present invention has been devised in view of these points, and is to position the variable nozzle unit with respect to the housing, suppress exhaust gas leakage from the intake side to the housing side of the turbine wheel, and heat heat to the housing. An object of the present invention is to provide a variable-capacity turbocharger capable of further improving assembling property with a heat-shielding positioning seal member that integrates the three functions of suppressing conduction.

In order to solve the above problems, the first invention comprises a turbine wheel that is rotationally driven by the exhaust gas of an internal combustion engine, a housing that rotatably supports the turbine wheel around its rotation axis at its tip, and the above. A plurality of variable nozzles arranged along the circumferential direction on the outer peripheral side of the turbine wheel and an inner diameter larger than the outer diameter of the tip portion of the housing are formed in an annular shape so as to cover the outer circumference of the tip portion. A variable displacement supercharger having a nozzle plate for holding a plurality of the variable nozzles, the outer peripheral surface of the housing tip, which is the outer peripheral surface of the tip portion of the housing, is located on the inner circumference of the nozzle plate. At least a part of the inner peripheral surface of the formed plate is opposed to the inner peripheral surface of the plate in the direction along the rotation axis, and a disk-shaped heat shield is formed between the tip of the housing and the turbine wheel. A positioning seal member is provided, and the heat shield positioning seal member is curved so as to be continuous convex toward the side of the housing along the direction of the rotation axis and comes into contact with the outer peripheral surface of the tip of the housing. An annular inner annular convex curved portion fitted to the outer peripheral side of the tip end portion of the housing and a continuous inner annular convex curved portion provided on the outer peripheral side of the inner annular convex curved portion along the direction of the rotation axis. From the annular outer annular convex curved portion that is curved so as to be convex and fitted to the inner peripheral side of the nozzle plate so as to come into contact with the inner peripheral surface of the plate, and the inner annular convex curved portion. It is a variable displacement type supercharger having a heat shield portion extending to the inner peripheral side and covering at least a part of the end surface of the tip end portion of the housing.

The second invention is the variable displacement turbocharger according to the first invention, in which the outer annular convex curved portion is convex toward the turbine wheel along the direction of the rotation axis. It is a variable capacity turbocharger that is curved like this.

A third invention is the variable-capacity supercharger according to the second invention, wherein the inner peripheral surface of the nozzle plate serves as an end portion on the side of the housing in the direction of the rotation axis. A large-diameter plate large-diameter inner peripheral surface formed on the inner peripheral surface of the nozzle plate and facing the outer peripheral surface of the tip of the housing and adjacent to the plate large-diameter inner peripheral surface in the direction of the rotation axis. A plate small diameter inner peripheral surface formed on the side of the turbine wheel and having a diameter smaller than that of the plate large diameter inner peripheral surface, and a diameter formed between the plate large diameter inner peripheral surface and the plate small diameter inner peripheral surface. The plate has a stepped surface along the direction, and the outer annular convex curved portion of the heat shield positioning seal member is in contact with both the large-diameter inner peripheral surface of the plate and the stepped surface of the plate. , Variable capacity type supercharger.

A fourth invention is a variable-capacity turbocharger according to any one of the first to third inventions, wherein the heat shield is located at any position in the radial direction of the housing. A variable-capacity turbocharger that is curved toward the housing in the direction of the rotation axis so as to come into contact with the end face.

A fifth invention is a variable displacement turbocharger according to any one of the first to fourth inventions, wherein the heat shield positioning seal member is made of a metal having elastic force and heat resistance. It is a variable capacity turbocharger that is formed in the above.

According to the first invention, the three functions of positioning the variable nozzle unit with respect to the housing, suppressing exhaust gas leakage from the intake side to the housing side of the turbine wheel, and suppressing heat conduction to the housing are integrated. The heat shield positioning seal member can be used to further improve the assembling property.

According to the second invention, the heat shield positioning seal member can be easily fitted inside the nozzle plate by moving the outer annular convex curved portion toward the turbine wheel side along the inner peripheral surface of the plate. ..

According to the third invention, the heat shield positioning seal member can be positioned with respect to the nozzle plate in the direction of the rotation axis of the turbine wheel.

According to the fourth invention, by contacting the heat shield portion with the end surface of the housing, it is possible to prevent vibration from being generated due to the rotation of the turbine wheel.

According to the fifth invention, the heat shield positioning seal member is not destroyed even when exposed to high temperature exhaust gas, the variable nozzle unit is positioned with respect to the housing side, and the turbine wheel is positioned from the intake side to the housing side. Exhaust gas leakage can be suppressed.

It is sectional drawing explaining the whole structure of the variable capacity type supercharger of 1st Embodiment. It is sectional drawing explaining the detail of the variable capacity type supercharger of 1st Embodiment. It is sectional drawing explaining the detail of the variable capacity type supercharger of 2nd Embodiment. It is an enlarged view explaining the variable capacity type supercharger described in Patent Document 1. FIG.

Hereinafter, examples of embodiments of the present invention will be described with reference to FIGS. 1 to 4.
[Structure of the variable capacity turbocharger 1 of the first embodiment (FIGS. 1 and 2)]
FIG. 1 is a cross-sectional view of a cross section including a rotation axis JK of a turbine wheel 5 of a variable displacement turbocharger 1 for a vehicle according to a first embodiment of the present invention. The variable-capacity turbocharger 1 for a vehicle according to an embodiment of the present invention uses the energy of exhaust gas from an internal combustion engine (not shown) to compress (supercharge) the air supplied to the internal combustion engine side. ).

As shown in FIG. 1, the variable capacity turbocharger 1 includes a turbine housing 3, a turbine wheel 5, a variable nozzle unit 10, a housing 20, and a heat shield positioning seal member 30.

The turbine wheel 5 is rotationally driven by the exhaust gas of an internal combustion engine, and is rotatably supported by a rotor shaft 7 at the tip 25 of the housing 20 around the rotation axis JK. A plurality of variable nozzles 11 are arranged on the outer peripheral side of the turbine wheel 5 along the circumferential direction, have an inner diameter larger than the outer diameter of the tip portion 25 of the housing 20 itself, and are annular so as to cover the outer circumference of the tip portion 25. It is held by the first nozzle plate 15 formed in.

The variable nozzle unit 10 includes a variable nozzle 11, a nozzle shaft 13A, a nozzle variable mechanism 13B, a first nozzle plate 15 (corresponding to a nozzle plate), and a second nozzle plate 19. The variable nozzle 11 is connected to the nozzle variable mechanism 13B via the nozzle shaft 13A to adjust the amount of exhaust gas supplied to the turbine wheel 5.

As shown in FIGS. 1 and 2, the outer peripheral surface of the housing tip, which is the outer peripheral surface of the tip 25 of the housing 20, is the inner peripheral surface 17 of the plate formed on the inner circumference of the first nozzle plate 15 and the rotation axis JK. At least a part of them face each other in the direction along the above.

The plate inner peripheral surface 17 has a plate large diameter inner peripheral surface 17A, a plate small diameter inner peripheral surface 17B, and a plate stepped surface 17C.

The plate large-diameter inner peripheral surface 17A has a large-diameter inner peripheral surface facing the housing tip outer peripheral surface 21 formed on the inner peripheral surface of the first nozzle plate 15 which is the end on the housing 20 side in the direction of the rotation axis JK. It is a face.

The plate small diameter inner peripheral surface 17B is an inner peripheral surface having a smaller diameter than the plate large diameter inner peripheral surface 17A formed on the turbine wheel 5 side so as to be adjacent to the plate large diameter inner peripheral surface 17A in the direction of the rotation axis JK. be.

The plate stepped surface 17C is a stepped surface formed between the plate large diameter inner peripheral surface 17A and the plate small diameter inner peripheral surface 17B and along the radial direction.

A heat shield positioning seal member 30 is provided between the tip portion 25 of the housing 20 and the turbine wheel 5. The heat shield positioning seal member 30 is made of a metal material having elastic force and heat resistance (for example, a nickel-based superalloy or the like), and is formed in a disk shape having a plate thickness of 0.1 mm to 0.3 mm. Further, the heat shield positioning seal member 30 has an inner annular convex curved portion 31, an outer annular convex curved portion 33, and a heat shield portion 35.

The inner annular convex curved portion 31 is an annular shape curved so as to be a continuous convex shape toward the housing 20 side along the direction of the rotation axis JK, and is in contact with the outer peripheral surface 21 at the tip of the housing. It is fitted on the outer peripheral side of the tip portion 25 of the housing 20.

The outer annular convex curved portion 33 is provided on the outer peripheral side of the inner annular convex curved portion 31 and is curved so as to be convex toward the continuous turbine wheel 5 along the direction of the rotation axis JK. It is fitted on the inner peripheral side of the first nozzle plate 15 so as to come into contact with the large-diameter inner peripheral surface 17A of the plate forming a part of the inner peripheral surface 17 of the plate. The outer annular convex curved portion 33 is in contact with both the large-diameter inner peripheral surface 17A of the plate and the stepped surface 17C of the plate.

The heat shield portion 35 extends toward the inner peripheral side of the inner annular convex curved portion 31 so as to cover at least a part of the housing end face 23 (corresponding to the end face) which is the end face of the housing 20 at the tip end portion 25 of the housing 20. It is installed. The heat shield portion 35 is curved so that any position in the radial direction faces the housing 20 side in the direction of the rotation axis JK so as to contact the housing end surface 23.

[Effect of heat shield positioning seal member (Fig. 2)]
FIG. 2 is an enlarged view illustrating the details of the variable capacity turbocharger 1 of the first embodiment. The arrow indicates the flow of exhaust gas.

As shown in FIG. 2, the inner annular convex curved portion 31 and the outer annular convex curved portion 33 seal a gap formed between the plate large-diameter inner peripheral surface 17A and the housing tip outer peripheral surface 21 to seal the turbine. Leakage of exhaust gas from the intake side of the wheel 5 to the housing 20 side can be suppressed. As a result, the variable displacement turbocharger 1 of the present invention can improve the performance of turbine efficiency.

In the heat shield positioning seal member 30, the outer annular convex curved portion 33 comes into contact with the plate large-diameter inner peripheral surface 17A, and the inner annular convex curved portion 31 contacts the outer peripheral surface 21 at the tip of the housing. By positioning the nozzle plate 15 in the radial direction, the variable nozzle unit 10 can be positioned in the radial direction.

The inner annular convex curved portion 31 and the outer annular convex curved portion 33 of the heat shield positioning seal member 30 form a substantially S-shaped shape in the cross section. Since the substantially S-shaped cross-sectional shape and the heat shield positioning seal member 30 are made of a material having elastic force, the variable nozzle unit 10 is housed by the inner annular convex curved portion 31 and the outer annular convex curved portion 33. It is elastically supported with respect to 20.

At room temperature (during assembly), the inner annular convex curved portion 31 and the outer annular convex curved portion 33 are elastically deformed (deformed in the shrinking direction), and the plate large-diameter inner peripheral surface 17A and the housing tip outer peripheral surface are in a state of being elastically deformed (deformed in the shrinking direction). It is fitted between 21 and 21. The inner annular convex curved portion 31 and the outer annular convex curved portion 33 elastically deformed in the contraction direction are elastically deformed in the radial direction to expand and contract, thereby causing thermal expansion at high temperature and thermal contraction at low temperature. Can be absorbed. As a result, the heat shield positioning seal member 30 can maintain the seal of the gap between the plate large diameter inner peripheral surface 17A (plate inner peripheral surface 17) and the housing tip outer peripheral surface 21, and the variable nozzle unit 10 with respect to the housing 20. The radial positioning of the can be maintained.

In the heat shield positioning seal member 30, the outer annular convex curved portion 33 comes into contact with the plate step surface 17C, and the heat shield positioning seal material 30 can be positioned in the direction of the rotation axis JK.

By covering the housing end face 23, the heat shield portion 35 can prevent the exhaust gas from the intake side of the turbine wheel 5 from directly hitting the housing end face 23 and prevent heat from being conducted to the housing 20. ..

[Structure of the variable capacity turbocharger 1X of the second embodiment (Fig. 3)]
In the second embodiment of the present invention, the shapes of the first nozzle plate and the housing are different from the shapes of the first nozzle plate 15 and the housing 20 (see FIGS. 1 and 2) of the first embodiment. This is an example of an embodiment applied to a capacity turbocharger.

FIG. 3 is a cross-sectional view of a cross section including the rotation axis JK of the turbine wheel 5 of the variable capacity turbocharger 1X for a vehicle according to the second embodiment. The arrow indicates the flow of exhaust gas.

The variable-capacity turbocharger 1X is a first nozzle plate 15X instead of the first nozzle plate 15 (see FIG. 2) with respect to the variable-capacity turbocharger 1 of the first embodiment, and the housing 20 ( The difference is that the housing 20X is used instead of (see FIG. 2). Hereinafter, the first nozzle plate 15X and the housing 20X will be mainly described.

The first nozzle plate 15X is different in that it is a plate inner peripheral surface 17X instead of the plate inner peripheral surface 17 (see FIG. 2). The plate inner peripheral surface 17X is a single inner peripheral surface, and does not have a plate large diameter inner peripheral surface 17A, a plate small diameter inner peripheral surface 17B, and a plate stepped surface 17C (see FIG. 2).

The housing 20X is different in that the housing tip outer peripheral surface 21X is used instead of the housing tip outer peripheral surface 21 (see FIG. 2). The outer peripheral surface 21X at the tip of the housing is a single outer peripheral surface and does not have a step.
● [Effect of the present invention]

As described above, the variable capacity turbocharger of the present invention positions the variable nozzle unit with respect to the housing, suppresses the leakage of exhaust gas from the intake side to the housing side of the turbine wheel, and heats the housing. Assembability can be further improved by a heat shield positioning seal member that integrates the three functions of suppressing conduction.

The variable capacity turbocharger of the present invention is not limited to the configuration, structure, etc. described in the present embodiment, and various changes, additions, and deletions can be made without changing the gist of the present invention. In particular, the shape of the inner peripheral surface of the first nozzle plate and the shape of the outer peripheral surface of the housing are not limited to the shapes described in the above embodiments, and include the inner annular convex curved portion and the outer annular convex curved portion. Any shape may be used as long as it forms a gap.

In the example of the embodiment of the present application, the heat shield portion 35 is in contact with the housing end surface 23 near the rotor shaft 7, but is not limited to this, and is on the inner peripheral side of the inner annular convex curved portion 31. If it is extended, it may or may not be in contact with the housing end face 23.

1, 1X Variable capacity turbocharger 3 Turbine housing 5 Turbine wheel 7 Rotor shaft 10 Variable nozzle unit 11 Variable nozzle 13A Nozzle shaft 13B Nozzle variable mechanism 15, 15X 1st nozzle plate (nozzle plate)
17, 17X Plate inner peripheral surface 17A Plate large diameter inner peripheral surface 17B Plate small diameter inner peripheral surface 17C Plate stepped surface 19 2nd nozzle plate 20, 20X Housing 21, 21X Housing tip outer peripheral surface 23 House end surface (end surface)
25 Tip part 30 Heat shield positioning seal material 31 Inner annular convex curved part 33 Outer annular convex curved part 35 Heat shield JK Rotating axis

Claims (5)

A turbine wheel that is rotationally driven by the exhaust gas of an internal combustion engine,
A housing that rotatably supports the turbine wheel around the axis of rotation at its tip,
A plurality of variable nozzles arranged along the circumferential direction on the outer peripheral side of the turbine wheel,
A nozzle plate having an inner diameter larger than the outer diameter of the tip portion of the housing and being formed in an annular shape so as to cover the outer circumference of the tip portion and holding a plurality of the variable nozzles.
It is a variable capacity turbocharger with
The outer peripheral surface of the tip of the housing, which is the outer peripheral surface of the tip of the housing, is at least partially opposed to the inner peripheral surface of the plate formed on the inner circumference of the nozzle plate in the direction along the rotation axis.
A disk-shaped heat shield positioning seal member is provided between the tip of the housing and the turbine wheel.
The heat shield positioning seal member is
A circle that is curved so as to be continuous convex toward the side of the housing along the direction of the rotation axis and fitted to the outer peripheral side of the tip portion of the housing so as to come into contact with the outer peripheral surface of the tip end portion of the housing. An annular inner annular convex curved portion and an annular
The inner peripheral side of the nozzle plate is provided on the outer peripheral side of the inner annular convex curved portion and is curved so as to have a continuous convex shape along the direction of the rotation axis so as to come into contact with the inner peripheral surface of the plate. An annular outer annular convex curved portion fitted into the
A heat shield that extends to the inner peripheral side of the inner annular convex curved portion and covers at least a part of the end surface of the tip portion of the housing.
have,
Variable capacity turbocharger. The variable capacity turbocharger according to claim 1.
The outer annular convex curved portion is curved so as to be convex toward the turbine wheel along the direction of the rotation axis.
Variable capacity turbocharger. The variable capacity turbocharger according to claim 2.
The inner peripheral surface of the nozzle plate is
A large-diameter plate large-diameter inner peripheral surface formed on the inner peripheral surface of the nozzle plate, which is an end portion on the side of the housing in the direction of the rotation axis, and facing the outer peripheral surface of the tip of the housing.
A plate small-diameter inner peripheral surface formed on the turbine wheel side so as to be adjacent to the plate large-diameter inner peripheral surface in the direction of the rotation axis, and having a diameter smaller than that of the plate large-diameter inner peripheral surface.
A plate stepped surface formed between the plate large-diameter inner peripheral surface and the plate small-diameter inner peripheral surface and along the radial direction,
Have and
The outer annular convex curved portion of the heat shield positioning seal member is
It is in contact with both the large-diameter inner peripheral surface of the plate and the stepped surface of the plate.
Variable capacity turbocharger. The variable capacity turbocharger according to any one of claims 1 to 3.
The heat shield is curved so that any position in the radial direction is in contact with the end face of the housing and is directed toward the housing in the direction of the rotation axis.
Variable capacity turbocharger. The variable capacity turbocharger according to any one of claims 1 to 4.
The heat shield positioning seal member is
Formed of elastic and heat resistant metal,
Variable capacity turbocharger.

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