JP7396955B2 - Variable capacity supercharger - Google Patents

Description

The present invention relates to a variable displacement supercharger.

As a supercharger for an internal combustion engine for a vehicle, there is a variable capacity supercharger that can obtain a high supercharging effect from a low rotation range to a high rotation range. A typical variable displacement supercharger consists of a housing (bearing housing), a turbine wheel rotatably disposed in the housing, and a variable nozzle that changes the flow path area of exhaust gas supplied to the turbine wheel. , is equipped with.

For example, in the variable capacity supercharger 101 of Patent Document 1 shown in FIG. (equivalent to a turbine wheel). Further, a tapered fitting portion 131 capable of tapered fitting is formed in the heat shield plate 130 at a position facing the tapered fitting portion 135 on the radially outer side of the fitting portion 121.

In the variable capacity supercharger 101, due to the difference in thermal expansion between the heat shield plate 130 and the bearing housing 120 at high temperatures (during operation), the tapered fitting part 135 and the tapered fitting part 131 come into contact with each other, and the tapered fitting part 135 and the tapered fitting part 131 come into contact with each other. A force is generated between the portion 135 and the tapered fitting portion 131. A component of the generated force along the rotation axis JK2 of the turbine impeller 105 pushes the heat shield plate 130 toward the variable nozzle 111, causing the contact portion 133 of the heat shield plate 130 and a part of the nozzle ring 115 to be pushed toward the variable nozzle 111. A seal can be created between the two. This prevents exhaust gas from leaking from the variable nozzle 111 side to the bearing housing 120, thereby preventing a decrease in turbine efficiency.

Japanese Patent Application Publication No. 2011-247189

In the variable capacity supercharger 101 described in Patent Document 1, at room temperature (during non-operation and warm-up operation), a gap is formed between the tapered fitting portion 135 and the tapered fitting portion 131 due to the difference in thermal expansion. This may occur, and it may not be possible to seal between the contact portion 133 and a portion of the nozzle ring 115. Furthermore, in the variable capacity supercharger 101, at room temperature (during non-operation and warm-up operation), the heat shield plate 130 contracts in the radial direction of the turbine impeller 105, causing a gap between the nozzle ring 115 and the heat shield plate 130. There may be a gap between the nozzle ring 115 and the bearing housing 120, which may make it impossible to position the nozzle ring 115 with respect to the bearing housing 120.

The present invention has been devised in view of these points, and is aimed at positioning a variable nozzle unit with respect to the housing, suppressing leakage of exhaust gas from the intake side of the turbine wheel to the housing side, and suppressing heat transfer to the housing. It is an object of the present invention to provide a variable capacity supercharger that can further improve assemblability using a heat shielding positioning seal member that integrates three functions: suppressing conduction.

In order to solve the above problems, a first invention provides a turbine wheel rotatably driven by exhaust gas of an internal combustion engine, a housing that supports the turbine wheel rotatably around a rotational axis at a distal end thereof, and a plurality of variable nozzles disposed along the circumferential direction on the outer peripheral side of the turbine wheel; and an annular shape having an inner diameter larger than an outer diameter of the tip of the housing and covering the outer periphery of the tip. and a nozzle plate holding a plurality of variable nozzles, the housing tip outer circumferential surface being an outer circumferential surface of the tip portion of the housing is located on the inner circumference of the nozzle plate. At least a portion of the formed inner peripheral surface of the plate faces the direction along the rotation axis, and a heat shield formed in a disk shape is provided between the tip end of the housing and the turbine wheel. A positioning seal member is provided, and the heat-insulating positioning seal member is curved so as to have a continuous convex shape toward the housing along the direction of the rotation axis, and comes into contact with the outer peripheral surface of the distal end of the housing. an annular inner annular convex curved portion fitted on the outer circumferential side of the distal end portion of the housing; and an annular inner annular convex curved portion provided on the outer circumferential side of the inner annular convex curved portion and continuous along the direction of the rotation axis. an annular outer annular convex curved portion that is curved to have a convex shape and is fitted into the inner circumferential side of the nozzle plate so as to contact the inner circumferential surface of the plate; The variable capacity supercharger further includes a heat shield part extending toward the inner peripheral side and covering at least a part of the end surface of the tip part of the housing.

A second invention is the variable capacity supercharger according to the first invention, wherein the outer annular convex curved portion is convex toward the turbine wheel along the direction of the rotation axis. It is a variable capacity supercharger that is curved like this.

A third invention is the variable displacement supercharger according to the second invention, wherein the inner circumferential surface of the nozzle plate is an end on the housing side in the direction of the rotation axis. a large-diameter inner circumferential surface of a large-diameter plate formed on the inner circumferential surface of the nozzle plate and facing the outer circumferential surface of the distal end of the housing; a small diameter inner circumferential surface of the plate formed on the side of the turbine wheel and having a smaller diameter than the inner circumferential surface of the large diameter plate; and a small diameter inner circumferential surface of the plate formed between the large inner circumferential surface of the plate and the inner circumferential surface of the plate small diameter. a plate step surface along the direction, and the outer annular convex curved portion of the heat-insulating positioning seal member is in contact with both the plate large-diameter inner circumferential surface and the plate step surface. , a variable capacity supercharger.

A fourth invention is the variable capacity supercharger according to any one of the first to third inventions, wherein the heat shield part is located at any position in the radial direction of the housing. The variable displacement supercharger is curved toward the housing in the direction of the rotational axis so as to contact an end surface.

A fifth invention is the variable capacity supercharger 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. This is a variable capacity supercharger made of

According to the first invention, three functions are integrated: positioning the variable nozzle unit with respect to the housing, suppressing leakage of exhaust gas from the intake side of the turbine wheel to the housing side, and suppressing conduction of heat to the housing. With the heat-insulating positioning seal member, ease of assembly can be further improved.

According to the second invention, by moving the outer annular convex curved portion toward the turbine wheel side along the inner peripheral surface of the plate, the heat shield positioning seal member can be easily fitted inside the nozzle 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 bringing the heat shield into contact with the end surface of the housing, it is possible to prevent vibrations from occurring as the turbine wheel rotates.

According to the fifth invention, the heat shield positioning seal member is not destroyed even when exposed to high temperature exhaust gas, and the positioning of the variable nozzle unit with respect to the housing side and the positioning of the variable nozzle unit from the intake side of the turbine wheel to the housing side are prevented. can suppress exhaust gas leaks.

FIG. 1 is a sectional view illustrating the overall configuration of a variable capacity supercharger according to a first embodiment. FIG. 2 is a sectional view illustrating details of the variable capacity supercharger of the first embodiment. FIG. 7 is a sectional view illustrating details of a variable capacity supercharger according to a second embodiment. FIG. 2 is an enlarged view illustrating a variable capacity supercharger described in Patent Document 1.

Examples of embodiments of the present invention will be described below with reference to FIGS. 1 to 4.
● [Configuration of variable capacity supercharger 1 of the first embodiment (FIGS. 1 and 2)]
FIG. 1 is a sectional view of a section including a rotation axis JK of a turbine wheel 5 of a variable capacity supercharger 1 for a vehicle according to a first embodiment of the present invention. A variable capacity supercharger 1 for a vehicle according to an embodiment of the present invention utilizes the energy of exhaust gas from an internal combustion engine (not shown) to compress (supercharge) air supplied to the internal combustion engine. ).

As shown in FIG. 1, the variable displacement supercharger 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 the internal combustion engine, and is supported by the rotor shaft 7 at the tip 25 of the housing 20 so as to be rotatable around the rotation axis JK. A plurality of variable nozzles 11 are arranged along the circumferential direction on the outer circumferential side of the turbine wheel 5, and have an annular shape having an inner diameter larger than the outer diameter of the tip end 25 of the housing 20 itself so as to cover the outer circumference of the tip end 25. The first nozzle plate 15 is formed in the first nozzle plate 15.

The variable nozzle unit 10 includes a variable nozzle 11, a nozzle shaft 13A, a variable nozzle 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 a variable nozzle mechanism 13B via a nozzle shaft 13A, and adjusts the amount of exhaust gas supplied to the turbine wheel 5.

As shown in FIGS. 1 and 2, the housing tip outer circumferential surface 21, which is the outer circumferential surface of the tip portion 25 of the housing 20, is connected to the plate inner circumferential surface 17 formed on the inner circumference of the first nozzle plate 15, and to the rotation axis JK. At least a portion thereof faces each other in the direction along.

The plate inner circumferential surface 17 has a plate large-diameter inner circumferential surface 17A, a plate small-diameter inner circumferential surface 17B, and a plate step surface 17C.

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

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

The plate step surface 17C is a step surface formed between the plate large diameter inner circumferential surface 17A and the plate small diameter inner circumferential surface 17B and extending in the radial direction.

A heat shield positioning seal member 30 is provided between the tip 25 of the housing 20 and the turbine wheel 5. The heat shielding positioning seal member 30 is formed into a disk shape with a thickness of 0.1 mm to 0.3 mm from a metal material having elasticity and heat resistance (for example, a nickel-based superalloy). 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 has an annular shape that is curved in 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 of the housing tip. It is fitted into 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. The first nozzle plate 15 is fitted into the inner circumferential side of the first nozzle plate 15 so as to contact the large-diameter inner circumferential surface 17A of the plate, which forms a part of the inner circumferential surface 17 of the plate. The outer annular convex curved portion 33 is in contact with both the plate large-diameter inner peripheral surface 17A and the plate step surface 17C.

The heat shielding part 35 extends inward from the inner annular convex curved part 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 of the distal end part 25 of the housing 20. It is set up. The heat shield portion 35 is curved toward the housing 20 in the direction of the rotation axis JK so that any position in the radial direction contacts the housing end surface 23.

[Effect of heat shield positioning seal member (Figure 2)]
FIG. 2 is an enlarged view illustrating details of the variable capacity supercharger 1 of the first embodiment. Note that the arrows indicate 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 the gap formed between the large-diameter inner circumferential surface 17A of the plate and the outer circumferential surface 21 at the tip of the housing. Leakage of exhaust gas from the intake side of the wheel 5 to the housing 20 side can be suppressed. Thereby, the variable capacity supercharger 1 of the present invention can improve the performance of the turbine efficiency.

The heat shielding positioning seal member 30 has an outer annular convex curved portion 33 in contact with the plate large-diameter inner circumferential surface 17A, an inner annular convex curved portion 31 in contact with the housing tip outer circumferential surface 21, and a first 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 cross section. Due to this substantially S-shaped cross-sectional shape and the heat shielding positioning seal member 30 being made of a material having elastic force, the variable nozzle unit 10 has an inner annular convex curved portion 31 and an outer annular convex curved portion 33. 20 is elastically supported.

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 direction of contraction), and the plate large-diameter inner circumferential surface 17A and the housing tip outer circumferential surface 21. The inner annular convex curved portion 31 and the outer annular convex curved portion 33, which are elastically deformed in the direction of contraction, expand and contract by elastically deforming in the radial direction, thereby reducing thermal expansion at high temperatures and thermal contraction at low temperatures. Can be absorbed. As a result, the heat shielding positioning seal member 30 can maintain sealing of the gap between the large-diameter plate inner circumferential surface 17A (plate inner circumferential surface 17) and the housing tip outer circumferential surface 21, and the variable nozzle unit 10 relative to the housing 20 can be maintained. can maintain its radial positioning.

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

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

● [Configuration of variable capacity supercharger 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 variable and 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 type supercharger.

FIG. 3 is a sectional view of a cross section including the rotational axis JK of the turbine wheel 5 of the variable capacity supercharger 1X for a vehicle according to the second embodiment. Note that the arrows indicate the flow of exhaust gas.

The variable displacement supercharger 1X has a first nozzle plate 15X instead of the first nozzle plate 15 (see FIG. 2), and a housing 20 ( The difference is that a housing 20X is used instead of the housing 20X (see FIG. 2). The first nozzle plate 15X and the housing 20X will be mainly described below.

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

The housing 20X is different in that the housing tip outer circumferential surface 21X is replaced by the housing tip outer circumferential surface 21 (see FIG. 2). The housing tip outer circumferential surface 21X is a single outer circumferential surface and does not have a step.
● [Effects of the present invention]

As explained above, the variable displacement supercharger of the present invention is capable of positioning the variable nozzle unit with respect to the housing, suppressing leakage of exhaust gas from the intake side of the turbine wheel to the housing side, and dissipating heat to the housing. Assemblability can be further improved by using a heat shield positioning seal member that combines the three functions of suppressing conduction.

The variable capacity supercharger of the present invention is not limited to the configuration, structure, etc. described in this 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 accommodate the inner annular convex curved portion and the outer annular convex curved portion. Any shape is acceptable as long as it forms a gap.

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

1, 1X Variable capacity supercharger 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 First 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 step surface 19 Second nozzle plate 20, 20X Housing 21, 21X Housing tip outer peripheral surface 23 Housing end surface (end surface)
25 Tip part 30 Heat shielding positioning sealing material 31 Inner annular convex curved part 33 Outer annular convex curved part 35 Heat shield part JK Rotation axis

Claims (5)

A turbine wheel that is rotationally driven by exhaust gas from an internal combustion engine,
a housing that rotatably supports the turbine wheel at its tip end about a rotational axis;
a plurality of variable nozzles arranged along the circumferential direction on the outer peripheral side of the turbine wheel;
a nozzle plate that has an inner diameter larger than an outer diameter of the tip of the housing, is formed in an annular shape so as to cover the outer periphery of the tip, and holds the plurality of variable nozzles;
A variable capacity supercharger having:
A housing tip outer circumferential surface that is an outer circumferential surface of the tip portion of the housing is at least partially opposed to a plate inner circumferential surface formed on an inner circumference of the nozzle plate in a direction along the rotation axis,
A heat shield positioning seal member formed in a disc shape is provided between the tip end of the housing and the turbine wheel,
The heat shielding positioning seal member is
a circle that is curved in a continuous convex shape toward the housing along the direction of the rotational axis and is fitted into the outer circumferential side of the distal end of the housing so as to contact the outer circumferential surface of the distal end of the housing; an annular inner annular convex curved portion;
an inner circumferential side of the nozzle plate, which is provided on the outer circumferential side of the inner annular convex curved portion, is curved to have a continuous convex shape along the direction of the rotational axis, and is in contact with the inner circumferential surface of the plate; an annular outer annular convex curved portion fitted into the
a heat shielding part that extends inward from the inner annular convex curved part and covers at least a part of the end surface of the distal end part of the housing;
have,
Variable capacity supercharger. The variable capacity supercharger 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 supercharger. The variable capacity supercharger according to claim 2,
The inner peripheral surface of the nozzle plate is
a large-diameter inner circumferential surface of a large-diameter plate formed on an inner circumferential surface of the nozzle plate that is an end on the side of the housing in the direction of the rotational axis, and facing the outer circumferential surface of the distal end of the housing;
a plate small-diameter inner circumferential surface formed on the turbine wheel side so as to be adjacent to the plate large-diameter inner circumferential surface in the direction of the rotation axis, and having a smaller diameter than the plate large-diameter inner circumferential surface;
a plate step surface along the radial direction formed between the plate large diameter inner circumferential surface and the plate small diameter inner circumferential surface;
It has
The outer annular convex curved portion of the heat shield positioning seal member is
in contact with both the large-diameter inner circumferential surface of the plate and the step surface of the plate;
Variable capacity supercharger. The variable capacity supercharger according to any one of claims 1 to 3,
The heat shielding portion is curved toward the housing in the direction of the rotation axis so that any position in the radial direction contacts an end surface of the housing.
Variable capacity supercharger. The variable capacity supercharger according to any one of claims 1 to 4,
The heat shielding positioning seal member is
Made of metal with elasticity and heat resistance,
Variable capacity supercharger.

Images