JP5136496B2 - Variable nozzle mechanism and variable displacement turbocharger - Google Patents

Description

 The present invention relates to a variable nozzle mechanism and a variable displacement turbocharger.

As a turbocharger capable of improving the engine performance over a wide range from a low rotation range to a high rotation range, for example, a variable capacity turbocharger described in Patent Document 1 is known.
The turbocharger is provided with an exhaust nozzle having a variable nozzle mechanism that guides exhaust gas introduced into the turbine scroll passage to the turbine impeller and adjusts the flow rate thereof. The variable nozzle mechanism has a drive ring that synchronously varies the angles of a plurality of annularly arranged variable nozzle vanes by rotating around an axis extending in a predetermined direction, and adjusting the exhaust gas passage area The flow rate is variable.

JP 2006-125588 A

 Incidentally, the drive ring is normally supported by a support ring that guides the rotation around the axis. As shown in FIG. 1 of Patent Document 1, the support ring includes a first guide member that guides one side of the drive ring in the axial direction and the outer diameter side of the drive ring, and the axial direction of the drive ring. A second guide member that guides the other side and the inner diameter side of the drive ring is combined.

 However, the support ring formed by combining these two members has a problem that it is difficult to improve the dimensional accuracy related to the guide characteristics. For example, a shift that occurs when the first guide member and the second guide member are combined using a fixture, and a gap between the first guide member and the second guide member that are manufactured through different processes. Dimensional accuracy deviations and the like that occur in this cause are obstructing the increase in dimensional accuracy of the entire support ring.

 The present invention has been made in view of such circumstances, and an object of the present invention is to provide a variable nozzle mechanism and a variable displacement turbocharger that can increase the rotational drive of a drive ring with high accuracy.

In order to solve the above problems, the present invention is a variable nozzle mechanism having a drive ring that synchronously varies the angles of a plurality of annularly arranged variable nozzle vanes by rotational driving about an axis extending in a predetermined direction. A substantially plate-shaped bottom surface portion that guides one side of the drive ring in the axial direction, and a substantially dish that is provided along an outer edge of the bottom surface portion and guides the outer diameter side of the drive ring. A plurality of first guide portions having a shape, a middle abdominal portion that is erected along the inner edge of the bottom surface portion and guides the inner diameter side of the drive ring, and the drive by bending the middle abdomen so as to face the bottom surface portion. And a second guide portion having a substantially tongue-like shape provided with a tip portion that guides the other side of the ring in the axial direction, wherein the first guide portion and the second guide portion are integrally formed. With To adopt formed.
By adopting this configuration, in the present invention, the substantially guide plate-shaped first guide part and the substantially tongue-shaped second guide part cooperate to guide both the axial side and the radial side of the drive ring, Then, by integrating the first guide portion and the second guide portion, the dimensional accuracy can be increased. Further, the reduction in the number of parts can contribute to cost reduction.

In the present invention, a configuration is adopted in which a convex portion for adjusting the guide width in the axial direction of the drive ring is formed on at least one of the bottom surface portion and the tip portion.
By adopting this configuration, in the present invention, it is possible to finely adjust the guide width between the tip portion and the bottom portion formed by bending, and it is possible to increase the dimensional accuracy.

Further, in the present invention, the drive ring has a plurality of grooves on the inner diameter side at predetermined intervals that engage one end of a link member connected to each of the variable nozzle vanes. In FIG. 4, a configuration is employed in which the groove portions are provided at intervals corresponding to the groove portions.
By adopting this configuration, in the present invention, the groove portion with which the one end portion of the link member is engaged is utilized, and the groove portion and the tip portion are overlapped in the axial direction, so that the drive ring can be assembled to the support ring. It becomes possible.

  Further, in the present invention, a bearing housing that rotatably supports the turbine impeller, a turbine housing in which a scroll passage for supplying exhaust gas to the turbine impeller is formed, and from the inside of the scroll passage to the turbine impeller side. An exhaust nozzle having a variable nozzle mechanism that adjusts the flow rate of the supplied exhaust gas, wherein the variable nozzle mechanism includes the variable nozzle mechanism described above. adopt.

According to the present invention, there is provided a variable nozzle mechanism having a drive ring that synchronously varies the angles of a plurality of annularly arranged variable nozzle vanes by rotational driving around an axis extending in a predetermined direction, A substantially ring-shaped first guide portion comprising a substantially ring-shaped bottom surface portion for guiding one side in the axial direction and an outer wall portion standing along the outer edge of the bottom surface portion for guiding the outer diameter side of the drive ring; A plurality of abdominal portions that are erected along the inner edge of the bottom surface portion and guide the inner diameter side of the drive ring; and the other side in the axial direction of the drive ring that is bent from the middle portion so as to face the bottom surface portion. A generally tongue-shaped second guide portion having a tip portion for guiding the side, and a support ring formed integrally with the first guide portion and the second guide portion is employed. By Thus, the substantially dish-shaped first guide portion and the generally tongue-shaped second guide portion cooperate to guide both sides in the axial direction and both radial directions of the drive ring, and these first guide portion and second guide portion. By integrating the dimensional accuracy, it becomes possible to increase the dimensional accuracy. Further, the reduction in the number of parts can contribute to cost reduction.
Therefore, in the present invention, a variable nozzle mechanism and a variable displacement turbocharger that can increase the accuracy of rotational driving of the drive ring can be obtained.

It is a schematic block diagram which shows the turbocharger in embodiment of this invention. It is a principal part enlarged view which shows the structure of the variable nozzle unit in embodiment of this invention. It is a front view which shows the structure of the synchronous mechanism in embodiment of this invention. It is a front view which shows the structure of the support ring in embodiment of this invention. FIG. 5 is a sectional view taken along line XX in FIG. 4. It is an arrow A figure in FIG.

Hereinafter, a configuration of a variable displacement turbocharger including a variable nozzle mechanism according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a turbocharger 1 according to an embodiment of the present invention. FIG. 2 is an enlarged view of the main part of FIG. 1 showing the configuration of the variable nozzle unit 27 in the embodiment of the present invention. FIG. 3 is a front view showing the configuration of the synchronization mechanism 43 in the embodiment of the present invention. In the following description, the arrow F in the drawings may be referred to as the front direction, and the reverse direction of the arrow F may be referred to as the rear direction.

As shown in FIG. 1, a turbocharger 1 according to the present embodiment is a variable capacity turbocharger that supercharges air supplied to an engine using energy of exhaust gas guided from an engine (not shown).
The turbocharger 1 includes a bearing housing 3, a turbine housing 5 connected to the front peripheral edge of the bearing housing 3 by fastening bolts 3a, and a compressor housing 7 connected to the rear peripheral edge of the bearing housing 3 by fastening bolts 3b. It has.

 A turbine shaft 11 extending in the front-rear direction is supported in the bearing housing 3 so as to be rotatable around the shaft via a plurality of bearings. A turbine impeller 13 is integrally connected to the front end portion of the turbine shaft 11, and a compressor impeller 15 is integrally connected to the rear end portion. The turbine impeller 13 is installed in the turbine housing 5, and the compressor impeller 15 is installed in the compressor housing 7.

The compressor housing 7 is formed with an air inlet 21 that opens to the rear side and is connected to an air cleaner (not shown). Further, between the bearing housing 3 and the compressor housing 7, a diffuser passage 23 that compresses and pressurizes air is formed in a substantially annular shape on the radially outer side of the compressor impeller 15. Further, the diffuser flow path 23 communicates with the intake port 21 through the installation location of the compressor impeller 15.
Furthermore, the compressor housing 7 has a compressor scroll passage 25 formed in a substantially annular shape on the outer side in the radial direction of the compressor impeller 15, and the compressor scroll passage 25 communicates with the diffuser passage 23. The compressor scroll passage 25 communicates with an intake port of an engine (not shown).

 The turbine housing 5 includes a turbine scroll passage 17 provided on the radially outer side of the turbine impeller 13 and a turbine housing outlet 19 which is an exhaust gas exhaust port. A variable nozzle unit (exhaust nozzle) 27 having a substantially annular shape is installed outside the turbine impeller 13 in the turbine housing 5 in the radial direction. A gap S is formed between the turbine housing 5 and the variable nozzle unit 27.

The turbine scroll passage 17 is formed in a substantially annular shape surrounding the turbine impeller 13 and communicates with a gas inlet (not shown) for introducing exhaust gas. Further, the turbine scroll channel 17 communicates with the nozzle channel 27 </ b> A in the variable nozzle unit 27. The gas inlet is connected to an exhaust port in an engine (not shown).
The turbine housing outlet 19 is open to the front side of the turbine housing 5 and communicates with the nozzle flow path 27 </ b> A through the installation location of the turbine impeller 13. The turbine housing outlet 19 is connected to an exhaust gas purification device (not shown).

Next, the configuration of the variable nozzle unit 27 will be described.
As shown in FIG. 2, the variable nozzle unit 27 includes a shroud ring 31 installed on the turbine housing 5 side, a nozzle ring 29 installed on the bearing housing 3 side facing the shroud ring 31, and a shroud ring 31. A plurality of nozzle vanes (variable nozzle vanes) 37 held between the nozzle ring 29 and a synchronization mechanism (variable nozzle mechanism) 43 that rotates the nozzle vanes 37 in synchronization with each other are provided. The nozzle flow path 27 </ b> A described above is formed between the shroud ring 31 and the nozzle ring 29.

The shroud ring 31 has a substantially cylindrical shape extending to the turbine housing outlet 19 side at a plate-shaped inner peripheral edge formed in a substantially ring shape. The shroud ring 31 is formed with a plurality of first holes 31a penetrating through the plate-like portion in the axial direction.
The nozzle ring 29 is a plate-like member formed in a substantially ring shape, and has a plurality of second hole portions 29a penetrating in the axial direction.

As shown in FIG. 1, the shroud ring 31 and the nozzle ring 29 are connected via a plurality of connecting pins 33 so as to form a predetermined interval. The connecting pin 33 penetrates the shroud ring 31, penetrates the nozzle ring 29, and protrudes rearward.
A support ring (described later) 35 is integrally provided on the rear side of the nozzle ring 29 by caulking a protruding connecting pin 33, and a flange portion 62a (outer peripheral edge portion) of the support ring 35 is provided in the turbine housing. 5 and the bearing housing 3 are sandwiched and supported. That is, the nozzle ring 29 is supported by the bearing housing 3 and the turbine housing 5 via the support ring 35.

As shown in FIG. 3, a plurality of nozzle vanes 37 are provided at equal intervals in the circumferential direction between the nozzle ring 29 and the shroud ring 31, and are each rotatable around an axis parallel to the rotation axis of the turbine impeller 13. . Each nozzle vane 37 has a nozzle vane body 38 formed so that the thickness gradually decreases from one predetermined side toward the opposite side, and a first protruding from the one side surface orthogonal to the one side of the nozzle vane body 38 to the front side. A vane shaft 41 and a second vane shaft 39 projecting rearward from a side surface facing the one side surface are provided.
As shown in FIG. 2, the first vane shaft 41 is rotatably inserted into the first hole 31 a of the shroud ring 31, and the second vane shaft 39 is rotated into the second hole 29 a of the nozzle ring 29. It penetrates freely and protrudes to the rear side of the nozzle ring 29.

 A connecting portion between the nozzle vane body 38 and the first vane shaft 41 is provided with a first flange 41a having a surface facing the nozzle ring 29, and a connecting portion between the nozzle vane body 38 and the second vane shaft 39 includes A second flange 39a having a surface facing the shroud ring 31 is provided. In addition, it is preferable that the external shape of the 1st collar part 41a is formed larger than the external shape of the 2nd collar part 39a, and the 1st collar part 41a and the 2nd collar part 39a are the 1st hole part 31a and the 2nd hole part, respectively. It is preferably formed so as to cover 29a.

Next, the configuration of the synchronization mechanism 43 that rotates each nozzle vane 37 in the present embodiment in synchronization will be described.
As shown in FIG. 1, on the rear side of the nozzle ring 29, a synchronization mechanism 43 is provided for rotating each nozzle vane 37 in synchronization.

 The synchronization mechanism 43 has a substantially ring shape and is fixed to the rear side of the nozzle ring 29 via a plurality of connecting pins 33, and a drive ring 47 supported by the support ring 35 so as to be rotatable about an axis. , A plurality of synchronization transmission links (link members) 51 for adjusting the angle of each nozzle vane 37 by rotation of the drive ring 47, a drive transmission link 59 for rotating the drive ring 47, and a turbine shaft at the lower front side of the bearing housing 3. 11 and a drive shaft 55 that is rotatably supported around an axis parallel to 11.

As shown in FIG. 3, the drive ring 47 has a plurality of synchronization engagement recesses (grooves) 49 that engage with one end of the synchronization transmission link 51 connected to each of the nozzle vanes 37 at a predetermined interval on the inner diameter side. doing. One end of the synchronization transmission link 51 is engaged with the synchronization engaging recess 49, and the other end is integrally connected to the second vane shaft 39 of each nozzle vane 37.
A driving engagement recess 53 having the same shape as the synchronization engagement recess 49 is formed on the inner diameter side of the drive ring 47. One end of the drive transmission link 59 engages with the drive engagement recess 53, and the other end is integrally connected to the drive shaft 55.
As shown in FIG. 1, a drive lever 57 is integrally connected to the opposite end of the drive transmission link 59 of the drive shaft 55, and an actuator such as a cylinder (not shown) is connected to the drive lever 57. ing.

Then, the structure of the support ring 35 in this embodiment is demonstrated with reference to FIGS.
FIG. 4 is a front view showing the configuration of the support ring 35 in the embodiment of the present invention. 5 is a cross-sectional view taken along line XX in FIG. FIG. 6 is an arrow A view in FIG.
As shown in FIG. 4, the support ring 35 includes a substantially dish-shaped first guide portion 60 in which the center portion of the bottom surface portion 61 is opened, and a plurality of substantially tongue-shaped second guide portions provided along the opening edge. 70 are integrally formed.

As shown in FIG. 5, the first guide portion 60 is erected along a substantially ring-shaped bottom surface portion 61 that guides one side (front side) of the drive ring 47 in the axial direction, and an outer edge of the bottom surface portion 61. And an outer wall portion 62 that guides the outer diameter side of the drive ring 47.
One second guide portion 70 is erected along the inner edge of the bottom surface portion 61 and is bent so as to oppose the bottom surface portion 61 from the middle abdominal portion 71 and guides the inner diameter side of the drive ring 47. And a front end portion 72 that guides the other side (rear side) of the drive ring 47 in the axial direction.
That is, the support ring 35 of the present embodiment guides both sides in the axial direction of the drive ring 47 by the bottom surface portion 61 and the tip portion 72 facing each other, and further, the outer wall portion 62 and the middle abdomen 71 facing each other. It is configured to guide both sides in the radial direction.

Returning to FIG. 4, the bottom surface portion 61 is provided with three insertion holes 61 a through which the connecting pins 33 are inserted, and are provided at substantially equal intervals on the inner diameter side. Further, on both sides of the position of the bottom surface portion 61 where the second guide portion 70 is provided, cut-up and recessed portions 61b are respectively provided. The recess 61b has a predetermined curvature and has a function of relaxing stress concentration.
A flange portion 62 a that is sandwiched between the turbine housing 5 and the bearing housing 3 is provided on the outer peripheral edge portion of the outer wall portion 62. Further, a drain hole 62b is provided in the outer wall portion 62 so as to penetrate in a radial direction at a symmetrical position with respect to the shaft.

The middle abdomen 71 is configured to be cut and raised at a substantially right angle with respect to the bottom surface part 61 and to face the outer wall part 62. Further, the distal end portion 72 is configured to bend from the middle abdominal portion 71 to the outer diameter side at a substantially right angle and to face the bottom surface portion 61.
The tip 72 has substantially the same shape as the synchronizing engagement recess 49 of the drive ring 47 in the axial direction (see FIG. 3). Further, the second guide portion 70 having the tip 72 is provided in the same phase as the synchronization engagement recess 49 of the drive ring 47, that is, at an interval corresponding to the synchronization engagement recess 49 in the axial direction. The drive ring 47 of the present embodiment utilizes a synchronization engagement recess 49 with which one end of the synchronization transmission link 51 is engaged, and the synchronization engagement recess 49 and the tip 72 are overlapped in the axial direction. And assembled to the support ring 35.

  Further, each of the bottom surface portion 61 and the tip portion 72 is formed with convex portions (61c, 72c) that protrude from each other in the facing direction (see, for example, FIG. 6). The convex portions 61c and the convex portions 72c protrude at a predetermined distance to adjust the guide width in the axial direction, and finely adjust the guide width between the front end portion 72 and the bottom surface portion 61 formed by bending by integral molding. Thus, the dimensional accuracy in the axial direction is increased.

Next, the operation of the turbocharger 1 in this embodiment will be described.
Exhaust gas discharged from the exhaust port of the engine is introduced into the turbine scroll passage 17 through the gas inlet of the turbine housing 5. Then, the exhaust gas is introduced from the turbine scroll passage 17 into the nozzle passage 27A.
The turbocharger 1 operates an actuator (not shown) according to the engine speed, that is, the flow rate of the exhaust gas introduced into the nozzle flow path 27A. The actuator rotates the drive shaft 55 around the axis via the drive lever 57 and rotates the drive ring 47 around the axis via the drive transmission link 59 provided at the end of the drive shaft 55.

 The drive ring 47 is guided by the support ring 35 on both sides in the axial direction and both sides in the radial direction and is rotationally driven in the circumferential direction. When the drive ring 47 is driven to rotate, the angle of each nozzle vane 37 is varied in synchronization via each synchronization transmission link 51, and the opening area of the nozzle flow path 27A is changed. And the flow volume of the exhaust gas which passes along 27 A of nozzle flow paths is adjusted with the change of this opening area.

 Since the support ring 35 of the present embodiment is formed by integrally forming the first guide portion 60 and the second guide portion 70, it is not necessary to combine the two members as in the conventional case, and the displacement at the time of combination is not necessary. Can be eliminated. Furthermore, it is not necessary to manufacture both in a separate manufacturing process, and the difference in dimensional accuracy between the two caused by the difference in the manufacturing process can be eliminated. Therefore, the overall dimensional accuracy of the support ring 35 is increased, and the drive ring 47 can be rotated with high accuracy. For this reason, the angle adjustment of each nozzle vane can be performed precisely, and as a result, the supercharging performance can be improved over a wide range from the low rotation range to the high rotation range.

 The exhaust gas that has passed through the nozzle flow path 27A is introduced to the installation location of the turbine impeller 13 and rotates the turbine impeller 13. Thereafter, the exhaust gas is discharged from the turbine housing outlet 19. When the turbine impeller 13 rotates, the compressor impeller 15 connected via the turbine shaft 11 rotates, and the air introduced from the intake port 21 is supplied to the diffuser flow path 23 and is pressurized. The pressurized air is supplied to the intake port of the engine through the compressor scroll passage 25 and is supercharged to the engine to improve the output of the engine.

Therefore, according to the above-described embodiment, the synchronization mechanism 43 includes the drive ring 47 that synchronously varies the angles of the plurality of annularly arranged nozzle vanes 37 by rotational driving around an axis extending in a predetermined direction. A substantially ring-shaped bottom surface portion 61 that guides one side of the drive ring 47 in the axial direction, and an outer wall portion 62 that stands up along the outer edge of the bottom surface portion 61 and guides the outer diameter side of the drive ring 47. A plurality of first guide portions 60 having a substantially dish shape, a middle abdominal portion 71 that is erected along the inner edge of the bottom surface portion 61 and guides the inner diameter side of the drive ring 47, and so as to face the bottom surface portion 61 from the middle abdominal portion 71. A second guide part 70 having a substantially tongue-like shape and having a distal end part 72 that bends and guides the other side of the drive ring 47 in the axial direction, and includes the first guide part 60 and the second guide part 70. Integrally molded By adopting the configuration in which the support ring 35 is provided, the first guide portion 60 having a substantially dish shape and the second guide portion 70 having a substantially tongue shape cooperate with each other in the axial direction of the drive ring 47 and By guiding both sides in the radial direction and integrating the first guide portion 60 and the second guide portion 70, it is possible to increase the dimensional accuracy. Further, the reduction in the number of parts can contribute to cost reduction.
Therefore, in the present invention, the synchronization mechanism 43 and the turbocharger 1 that can increase the rotational drive of the drive ring 47 with high accuracy are obtained.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

 DESCRIPTION OF SYMBOLS 1 ... Turbocharger, 3 ... Bearing housing, 5 ... Turbine housing, 13 ... Turbine impeller, 17 ... Turbine scroll flow path, 27 ... Variable nozzle unit (exhaust nozzle), 35 ... Support ring, 37 ... Nozzle vane (variable nozzle vane), 43 ... Synchronizing mechanism (variable nozzle mechanism), 49 ... Synchronizing engagement recess (groove), 51 ... Synchronizing transmission link (link member), 60 ... First guide section, 61 ... Bottom section, 61c ... Convex section, 62 ... outer wall part, 70 ... second guide part, 71 ... middle abdomen, 72 ... tip part, 72c ... convex part

Claims (4)

A variable nozzle mechanism having a drive ring that synchronously varies the angle of a plurality of annularly arranged variable nozzle vanes by rotational driving around an axis extending in a predetermined direction;
A substantially dish-shaped bottom surface portion that guides one side of the drive ring in the axial direction, and a substantially dish-shaped bottom surface portion that is provided along an outer edge of the bottom surface portion and guides the outer diameter side of the drive ring. A first guide part;
A middle abdomen that is erected along the inner edge of the bottom surface and guides the inner diameter side of the drive ring, and is bent so as to face the bottom surface from the middle abdomen, and the other side in the axial direction of the drive ring A second guide portion having a substantially tongue-like shape including a tip portion for guiding
A variable nozzle mechanism comprising a support ring in which the first guide portion and the second guide portion are integrally formed.   The variable nozzle mechanism according to claim 1, wherein a convex portion for adjusting a guide width in the axial direction of the drive ring is formed on at least one of the bottom surface portion and the tip portion. The drive ring has a plurality of grooves at predetermined intervals on the inner diameter side, which engage with one end of a link member connected to each of the variable nozzle vanes,
The variable nozzle mechanism according to claim 1 or 2, wherein the tip portions are provided at intervals corresponding to the groove portions in the axial direction. A bearing housing that rotatably supports the turbine impeller, a turbine housing in which a scroll passage for supplying exhaust gas to the turbine impeller is formed, and the exhaust gas supplied from the scroll passage to the turbine impeller side. An exhaust nozzle having a variable nozzle mechanism for adjusting a flow rate, and a variable capacity turbocharger,
A variable displacement turbocharger comprising the variable nozzle mechanism according to claim 1 as the variable nozzle mechanism.

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