Variable displacement turbocharger

Abstract

The invention relates to a variable-capacity turbocharger (C) comprising: a drive ring (125) with a main body section (125b) which has a ring-like shape; a section (125j) that is formed in an outer circumferential surface (125d) of the main body section (125b); a first projecting section (125e) and a second projecting section (125f) formed in the cutout section (125j) and projecting in a circumferential direction of the main body section (125b) and bent towards a central axis, wherein the first projecting section (125e) and the second projecting section (125f) are spaced apart from each other in the circumferential direction of the main body section (125b) such that a connecting plate (27) is arranged in a sandwich-like manner, on which a nozzle vane (24) is mounted; and a slot section (125q) which is positioned on a radially inner side of the first projection section (125e) and the second projection section (125f).

Description

Technical field

[0001] The present invention relates to a variable displacement turbocharger having connecting plates on which nozzle vanes are mounted. Background of the state of the art

[0002] Up to now, a variable displacement (variable capacity) turbocharger has been widely used. In such a turbocharger, numerous nozzle vanes are arranged in a ring within a flow channel, which serves to introduce exhaust gas from a turbine spiral flow channel to a turbine impeller. When shaft sections of the nozzle vanes are rotated by the force of an actuator, the angles of the nozzle vanes within the flow channel change along with the rotation of the shaft sections. By changing the angle of the nozzle vanes, a flow channel width (the so-called nozzle throat width) is altered, and the flow rate of the exhaust gas flowing through the flow channel is controlled.

[0003] More precisely, the shaft sections of the nozzle vanes are axially supported by shaft holes formed in a nozzle ring. Connecting plates are mounted on the end sections of the shaft sections that project from the nozzle ring. A drive ring has a main body section with an annular shape. The main body section of the drive ring sits on a cylindrical section that projects axially from a main body section of the nozzle ring. Furthermore, in a turbocharger described, for example, in Patent Document 1, first and second projection sections are formed on the main body section of the drive ring. The first and second projection sections project from the main body section toward the side of the connecting plate.The first and second projecting sections are spaced apart in a circumferential direction and face each other in such a way that the connecting plate is arranged in a sandwich-like configuration. When the drive ring is rotated by the force of the actuator, the connecting plates are pressed (pressed) through the projecting sections of the drive ring. The connecting plates pivot, and the shaft sections and nozzle vanes are thus rotated. List of state-of-the-art patent documents Patent document 1: WO 2011 / 068 267 A1 Patent document 2: DE 10 2008 000 508 A1 Patent document 3: DE 10 2012 106 789 A1 Patent document 4: WO 2010 / 120 028 A1

[0004] DE 10 2008 000 508 A1 discloses an exhaust gas turbocharger for an internal combustion engine with adjustable guide vanes, wherein the guide vanes are rotatably mounted in a first support ring of the exhaust gas turbocharger and are coupled to each other via an adjusting ring, wherein the guide vanes each comprise a toothed disc segment, wherein the adjusting ring has a toothing, wherein the guide vanes are coupled to the adjusting ring via the toothed disc segments and the toothing of the adjusting ring, wherein a bearing pin is formed on each of the guide vanes, and wherein the adjusting ring is mounted directly or indirectly on the bearing pins of at least three guide vanes.

[0005] DE 10 2012 106 789 A1 discloses an adjustable guide vane assembly for a turbine, comprising a bearing ring with a plurality of guide vanes, wherein the guide vanes are rotatably mounted on the bearing ring by means of guide vane shafts, wherein an adjusting lever can be assigned to the guide vane shaft, which is designed to engage in a rotary ring, wherein the rotary ring has a recess for receiving the adjusting lever, characterized in that a first area of ​​the rotary ring is designed for axial and / or radial mounting of the rotary ring and a second area of ​​the rotary ring has the recesses, wherein the first area and the second area are positioned radially and axially apart from each other.

[0006] WO 2010 / 120 028 A1 discloses a nozzle arrangement for a variable geometry exhaust gas turbocharger. A synchronizing ring with multiple connecting parts for joining actuating elements enables a reduction in the production costs of such synchronizing rings and a longer service life of the connecting parts of the synchronizing ring. Summary Technical Problem

[0007] As described above, in the nozzle drive mechanism of the associated prior art, the drive ring rotates during operation. The projecting sections press against the connecting plates. When the projecting sections press against the connecting plates, excessive stress concentration may occur at the base end sections of the projecting sections.

[0008] Therefore, it is an object of the present invention to create a variable-capacity turbocharger (variable-displacement turbocharger) that can mitigate stress concentration. Solution to the problem

[0009] To solve the aforementioned problem, according to an embodiment of the present invention, a variable-capacity turbocharger (variable displacement / variable capacity turbocharger) is provided, comprising: a drive ring with a main body section having a ring-like shape; a first projection section and a second projection section formed on the main body section and spaced apart from each other in a circumferential direction of the main body section such that a connecting plate is sandwiched together on which a nozzle vane is mounted; and a cutout section formed on a section of the main body section between the first projection section and the second projection section.

[0010] The variable-capacity turbocharger may further include a nozzle ring having a shaft hole designed to axially support a shaft section connecting the nozzle vane and the connecting plate, and designed to support the main body section of the drive ring.

[0011] The first projection section and the second projection section extend radially outwards from an outer circumferential surface of the drive ring and are bent towards a central axis direction of the drive ring.

[0012] A first outer circumferential surface of the drive ring, which is positioned between the first projection section and the second projection section, can be positioned on a radially inner side with respect to a second outer circumferential surface, which is positioned on the outside (outside of) the first projection section and the second projection section.

[0013] The variable capacity turbocharger may further have a first connecting section which has a curved surface connecting a base end section of both the first projection section and the second projection section and the first outer circumferential surface.

[0014] The variable-capacity turbocharger may also have a second connecting section which has a curved surface connecting the base end section and the second outer circumferential surface. Effects of the invention

[0015] According to the present invention, the stress concentration can be mitigated (reduced). Brief description of the drawings Fig. Figure 1 shows a schematic sectional view of a variable displacement turbocharger. Fig. Figure 2 shows a perspective exploded view of a jet propulsion mechanism. Fig. Figure 3 shows an explanatory view illustrating a setup for limiting the movement of a drive ring using guide pins. Fig. Figure 4 shows a perspective view to illustrate a state after the jet propulsion mechanism has been assembled. Fig. Figure 5(a) shows a section view to illustrate a section in dashed lines from Fig. 1, and Fig. 5(b) shows a section view to represent a section in a dashed line with a point from Fig. 1. Fig. Figure 6 shows an explanatory view illustrating a counterbore groove. Fig. 7(a) shows a front view of the drive ring, and Fig. Figure 7(b) shows a perspective view of the drive ring. Fig. Figure 8 shows a cropped, enlarged view of the drive ring. Fig. Figure 9(a) shows a view illustrating a first projection section and a second projection section of a drive ring of a comparative example from a radially outer side of a main body section. Fig. Figure 9(b) shows a view illustrating a first projection section and a second projection section of the drive ring in the exemplary embodiment, viewed from the radially outer side of a main body section. Fig. Figure 10(a) shows a front view of a drive ring according to the invention, and Fig. Figure 10(b) shows a perspective view of the drive ring according to the invention. Fig. Figure 11 shows a section-like enlarged view of the drive ring of the first modification example. Fig. Figure 12(a) shows a front view of a drive ring of a modified example, and Fig. Figure 12(b) shows a perspective view of the drive ring of the modified example. Fig. Figure 13(a) shows a section-like enlarged view of the drive ring before sections of the modified example are formed, and Fig. Figure 13(b) shows a section-like enlarged view of the drive ring after the section sections of the modification example have been formed. Description of the exemplary embodiment

[0016] An embodiment of the present invention is described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values ​​of the embodiment are merely examples used to facilitate understanding, and the present invention is in no way limited by them unless otherwise specifically stated. Elements with substantially the same functions and configurations are designated here and in the drawings by the same reference numerals to avoid repetition. Furthermore, elements not directly related to the present invention have been omitted.

[0017] Fig. Figure 1 shows a schematic sectional view of a variable displacement turbocharger C (variable capacity turbocharger). In the following description, the direction indicated by the in Fig. Arrow L, shown in Figure 1, indicates the left side of the variable displacement turbocharger C. The direction indicated by the arrow is shown in Figure 1. Fig. The arrow R shown in Figure 1 corresponds to the right side of the variable displacement turbocharger C. As shown in Figure 1, this is represented by the arrow R. Fig. As shown in Figure 1, the variable displacement turbocharger C has a turbocharger main body 1. The turbocharger main body 1 has a bearing housing 2, a turbine housing 4, and a compressor housing 6. The turbine housing 4 is coupled to the left side of the bearing housing 2 by fastening screws 3. The compressor housing 6 is coupled to the right side of the bearing housing 2 by fastening screws 5.

[0018] The bearing housing 2 has a receiving hole 2a. The receiving hole 2a penetrates the bearing housing in a right- and left-pointing direction of the variable displacement turbocharger C. A shaft 8 is axially supported such that it is supported by a radial bearing 7 (in the present embodiment, a semi-floating bearing, which is mounted in Fig. A turbine impeller 9 (shown as an example) is rotatable and is mounted in the receiving hole 2a. A turbine impeller 9 is mounted (attached) to a left end section of the shaft 8. The turbine impeller 9 is mounted in the turbine housing 4 so that it is rotatable. Furthermore, a compressor impeller 10 is mounted (attached) to a right end section of the shaft 8. The compressor impeller 10 is mounted in the compressor housing 6 so that it is rotatable.

[0019] The compressor housing 6 has a suction port (suction opening) 11. The suction port 11 is open on the right side of the variable displacement turbocharger C. The suction port 11 is connected to an air cleaning device (not shown). A diffuser flow channel 12, designed to increase air pressure, is formed by the facing surfaces of the bearing housing 2 and the compressor housing 6. The diffuser flow channel 12 is annular, extending radially from an inner to an outer surface along the shaft 8. The diffuser flow channel 12 communicates radially with the suction port 11 on the inner surface via the compressor impeller 10.

[0020] Furthermore, the compressor housing 6 has a compressor spiral flow channel 13. The compressor spiral flow channel 13 has an annular shape. For example, the compressor spiral flow channel 13 is positioned on the outside in the radial direction of the shaft 8 with respect to the diffuser flow channel 12. The compressor spiral flow channel 13 communicates with a suction port (inlet) of an internal combustion engine (not shown). The compressor spiral flow channel 13 also communicates with the diffuser flow channel 12. When the compressor impeller 10 is rotated, air is drawn into the compressor housing 6 through the suction port 11. The air drawn in through the suction port 11 is accelerated and pressurized as it flows through the blades of the compressor impeller 11.The air, which has been accelerated and pressurized, undergoes a pressure increase (pressure recovery) in the diffuser flow channel 12 and the compressor spiral flow channel 13, and is introduced to the combustion engine.

[0021] Furthermore, a gap 14 is formed between the facing surfaces of the bearing housing 2 and the turbine housing 4. The gap 14 is a space that defines a flow channel “x” which allows the nozzle vanes 24 described below to be arranged within it and enables exhaust gas to flow through it. The gap 14 is annular in shape, extending from an inner to an outer surface in the radial direction of the shaft 8 (turbine impeller 9).

[0022] Furthermore, a discharge port (discharge opening) 16 is formed in the turbine housing 4. The discharge port 16 faces a front side of the turbine impeller 9. The discharge port 16 communicates with the turbine spiral flow channel 15 via the intermediary action of the turbine impeller 9. The discharge port 16 is connected to an exhaust gas cleaning device (not shown).

[0023] The turbine spiral flow channel 15 communicates with a (not shown) gas inlet port (gas inlet opening). Exhaust gas emitted from the combustion engine is introduced into the gas inlet port. The turbine spiral flow channel 15 also communicates with the flow channel "x". Thus, the exhaust gas introduced into the turbine spiral flow channel 15 via the gas inlet port flows through the flow channel "x". The exhaust gas that has flowed through the flow channel "x" is introduced to the discharge port 16 by the intermediate action of the turbine impeller 9. That is, the flow channel "x" is a channel that extends from the turbine spiral flow channel 15 to the turbine impeller 9. The exhaust gas causes the turbine impeller 9 to rotate as it flows from the flow channel "x" to the discharge port 16. A rotational force from the turbine impeller 9 is transmitted to the compressor impeller 10 by means of the intermediate action of the shaft 8.The rotational force of the compressor impeller 10 increases the pressure of the air, and the air is introduced to the intake port of the combustion engine.

[0024] At this point, when the flow rate of the exhaust gas introduced into the turbine housing 4 changes, the rotational speeds of the turbine impeller 9 and the compressor impeller 10 change. In some cases, depending on the operating condition of the internal combustion engine, the air, whose pressure has been increased to a desired level, cannot be sufficiently introduced to the intake port of the internal combustion engine. Therefore, a nozzle drive mechanism 20 is provided in the variable displacement turbocharger C.

[0025] The nozzle drive mechanism 20 modifies the flow channel width (hereinafter described as the nozzle throat width) of the flow channel “x” of the turbine housing 4. The nozzle drive mechanism 20 changes the flow velocity of the exhaust gas introduced into the turbine impeller 9 according to the exhaust gas flow rate. More precisely, when the rotational speed of the internal combustion engine is low and the exhaust gas flow rate is low, the nozzle drive mechanism 20 reduces the opening degree of the nozzle of the flow channel “x”. In this way, the flow velocity of the exhaust gas introduced to the turbine impeller 9 is increased. The turbine impeller 9 can rotate even at a low flow rate. A diagram of the turbine drive mechanism 20 is described below.

[0026] Fig. Figure 2 shows a perspective exploded view of the jet propulsion mechanism 20. As this is shown in Fig. As shown in Figure 2, the nozzle drive mechanism 20 has a plate 21. The plate 21 has a plate hole 21a. The plate hole 21a penetrates the plate 21 in an axial direction of the shaft 8 (hereinafter referred to as the "axial direction"). The plate 21, for example, has a flat plate shape with a circular cross-section in a direction perpendicular to the axial direction of the shaft 8.

[0027] On an outer circumferential surface of the plate 21, plate pin holes 21b are formed. The plate pin holes 21b penetrate the plate 21 in the axial direction. A plurality of (in the example of Fig. (2 there are three) Plate pin holes 21b are spaced apart from each other in a circumferential direction of the plate 21. The one ends of pins 22 are each inserted through the plate pin holes 21b.

[0028] The nozzle ring 23 is located on the side of the compressor impeller 10 (right side in Fig. 1) positioned relative to the plate 21. The nozzle ring 23 has a main body 23b. The main body 23b has a ring-like shape. An annular hole 23a is formed in the main body 23b. The annular hole 23a extends through the main body 23b in the axial direction. A cylindrical section 23c is formed on a section of the main body 23b on a side opposite the plate 21. The cylindrical section 23c projects from the main body 23b to a side facing away from the plate 21.

[0029] A projecting section 23e is formed on an outer circumferential surface 23d of the main body 23b. The projecting section 23e extends circumferentially around the main body 23b. The projecting section 23e projects towards the outer surface of the main body 23b (cylindrical section 23c) when viewed radially. Ring pin holes 23f are formed in sections of the main body 23b facing the plate pin holes 21b of the plate 21. The ring pin holes 23f extend through the main body 23b in the axial direction. Counterbore grooves 23g are formed in the main body 23b on one side of the cylindrical section 23c. The ring pin holes 23f are open in the counterbore grooves 23g. The pins 22 are inserted into the ring pin holes 23f.

[0030] A large-diameter section 22c is formed between the two end sections 22a and 22b in the pin 22. The outer diameter of the large-diameter section 22c is larger than the outer diameters of both end sections 22a and 22b. The end sections 22a of the pins 22 are inserted into the plate pin holes 21b. The large-diameter section 22c is held in contact with a surface of the plate 21 that faces the nozzle ring 23. The insertion positions of the pins 22 with respect to the plate pin holes 21b are thus determined. Similarly, the end sections 22b of the pins 22 are inserted into the ring pin holes 23f. The large-diameter section 22c is held in contact with a surface of the nozzle ring 23 that faces the plate 21. In such a way the insertion positions of the pins 22 are determined in relation to the ring pin holes 23f.On this occasion, sections 22d and 22e with large diameters at their ends on the outer sides of the two end sections 22a and 22b of the pin 22 are shown. As an example, when the pins 22 are assembled on the plate 21 or the nozzle ring 23 by crimping, the shapes of the pins 22 after crimping are shown. The shape of the pin 22 before insertion into the plate pin hole 21b of the plate 21 or the ring pin hole 23f of the nozzle ring 23 is, for example, such that pin sections having the same radii as those of the two end sections 22a and 22b of the pin 22 are formed to extend to the end sections furthest from the end.

[0031] In this way, an oriented gap (facing gap) between the plate 21 and the nozzle ring 23 is defined by the pins 22. The flow channel “x” is formed as the gap through which the plate 21 and the nozzle ring 23 face each other. That is, an axial length of the flow channel “x” is defined by the pins 22.

[0032] Guide holes 23i are open on an axial end face 23h (on the side opposite the plate 21) in the cylindrical section 23c of the nozzle ring 23. A plurality of (in the example of Fig. (2 there are three) guide holes 23i are spaced apart circumferentially in the cylindrical section 23c. In addition, shaft holes 23j are formed in the nozzle ring 23. The shaft holes 23j extend through the main body 23b and the cylindrical section 23c in the axial direction. A plurality of (in the example of Fig. 2 (there are eleven) wave holes 23j are spaced apart in the circumferential direction of the main body 23b.

[0033] The nozzle vanes 24 are positioned in the space (namely the flow channel “x”) between the plate 21 and the nozzle ring 23. In other words, the plate 21 faces the nozzle ring 23 on one side of a nozzle vane 24. A multitude of (in the example of Fig. 2 (there are eleven) nozzle vanes 24 are spaced apart in the circumferential direction (the direction of rotation of the turbine wheel 9) of the main body 23b similarly to the shaft holes 23j.

[0034] A shaft section 24a is formed on the nozzle vane 24. The shaft section 24a projects towards one side of a nozzle ring 23. The shaft section 24a is inserted into the shaft hole 23j such that it is axially supported (in a unilaterally clamped state). The above describes the case in which the shaft sections 24a are axially supported by the nozzle ring 23. However, the shaft sections 24a can also extend towards the side of the plate 21, and holes designed to axially support the shaft sections 24a can be formed in the plate 21.

[0035] The drive ring 25 has a main body section 25b with a ring-like shape. A drive hole 25a is formed in the main body section 25b. The drive hole 25a extends through the main body section 25b in the axial direction. The inner diameter of the drive hole 25a is slightly larger than the outer diameter of the cylindrical section 23c of the nozzle ring 23. The cylindrical section 23c is inserted into the drive hole 25a of the drive ring 25. In this way, the drive ring 25 is supported by the outer circumferential surface 23d of the cylindrical section 23c so that it is rotatable.

[0036] A guide pin 26 has a head section 26a and a section 26b with a small diameter. The section 26b with the small diameter has an outer diameter that is smaller than that of the head section 26a. The section 26b with the small outer diameter is, for example, press-fitted into the guide hole 23i (is press-fitted in it) and is held therein.

[0037] Fig. Figure 3 shows an explanatory view illustrating a setup for limiting the movement of the drive ring 25 using the guide pins 26. Fig. Figure 3 shows the nozzle ring 23, the drive ring 25 and the guide pins 26 of the nozzle drive mechanism 20 extracted and shown.

[0038] As this is in Fig. As shown in Figure 3, the cylindrical section 23c of the nozzle ring 23 is arranged inside (on the inner circumferential side) of the drive hole 25a of the drive ring 25. The guide holes 23i (see Figure 3) are located in the center of the drive ring 25. Fig. 2) are positioned on the radially inner side of the drive ring 25. The small-diameter sections 26b (see Fig. 2) The guide pins 26 are press-fitted in the guide holes 23i. The head sections 26a of the guide pins 26 extend slightly towards the radially outer side with respect to the drive holes 25a of the drive ring 25. An axial movement of the drive ring 25 is limited by a portion of the head section 26a that faces the drive ring 25 in the axial direction (and is held in contact with it).

[0039] Furthermore, inner circumferential grooves 25c are formed on an inner circumferential surface of the drive hole 25a. The inner circumferential grooves 25c are recessed towards the radially outer side. The inner circumferential grooves 25c are spaced apart in the circumferential direction, like many of the guide pins 26. For example, the nozzle ring 23 and the drive ring 25 are rotated relative to each other such that a rotational phase of one of the inner circumferential grooves 25c coincides with the head section 26a of the guide pin 26. In this case, the other inner circumferential grooves 25c each coincide with other guide pins 26 with respect to the rotational phase. The inner circumferential grooves 25c are deeper towards the radially outer side than the head sections 26a. In other words, the head section 26a of the guide pin 26 can pass through the interior of the inner circumferential groove 26c in the axial direction.Therefore, the drive ring 25 can be mounted on and removed from the nozzle ring 23 in a state in which the rotation phases of the guide pins 26 and the inner circumferential grooves 25c coincide.

[0040] For example, the guide pins 26 are press-fitted into the guide holes 23i before the drive ring 25 is mounted on the nozzle ring 23. At this point, the inner circumferential grooves 25c of the drive ring 25 are aligned so that they face the head sections 26a of the guide pins 26. In this way, the drive ring 25 can be installed on the nozzle ring 23. The guide pins 26 can be press-fitted into the guide holes 23i before the pins 22 and the like are mounted on the nozzle ring 23. As a result, deformations of the pins 22 and the like, caused by the press fit of the guide pins 26, are avoided. Control of the press-fit load is not required.More precisely, the simplicity of the process increases compared to a case in which the press fit load is handled in such a way that the guide pins 26 are press-fitted until the guide pins 26 come into contact with the bottom surfaces of the guide holes 23i or the like.

[0041] Furthermore, for example, first projecting sections 25e, second projecting sections 25f, a third projecting section 25g, and a fourth projecting section 25h are formed on the main body section 25b of the drive ring 25. The first projecting sections 25e, the second projecting sections 25f, the third projecting section 25g, and the fourth projecting section 25h project radially outwards from the outer circumferential surface 25d. The first projecting sections 25e, the second projecting sections 25f, the third projecting section 25g, and the fourth projecting section 25h project axially to a side opposite the nozzle ring 23 (the side of the connecting plate 27 described below).

[0042] A large number (as many as the number of nozzle blades 24, which in the example of Fig. 3 (eleven) pairs of the first projection section 25e and the second projection section 25f are formed, for example, at uniform intervals in the circumferential direction of the main body section 25b. A separation interval between the first projection section 25e and the second projection section 25f in each of the pairs is slightly larger than the width of a distal end section 27d of the corresponding nozzle vane 24 described below. Furthermore, the separation intervals of the respective pairs of the first projection section 25e and the second projection section 25f can be approximately equal. In addition, a separation interval between the first projection section 25e and the second projection section 25f of adjacent pairs can be larger than the separation interval of each of the pairs of the first projection section 25e and the second projection section 25f.

[0043] The main body section 25b has a third projecting section 25g and a fourth projecting section 25g. The third projecting section 25g and the fourth projecting section 25h are arranged between a pair of the first projecting section 25e and the second projecting section 25f and an adjacent pair of the first projecting section 25e and the second projecting section 25f.

[0044] With renewed reference to Fig. 2. The shaft section 24a is longer in the axial direction than the shaft hole 23j. A distal end section 24b of the shaft section 24a projects from the shaft hole 23j to a side opposite the nozzle vanes 24. The distal end sections 24b of the shaft sections 24a, which project from the shaft holes 23j of the nozzle ring 23, are inserted into the drive holes 25a of the drive ring 25 and are then inserted into the connecting plates 27.

[0045] The connecting plates 27 are provided in the same number as the number of nozzle vanes 24 on one side, opposite the nozzle vanes 24 with respect to the nozzle ring 23. The connecting plate 27 has a mounting section 27b. A plate hole 27a is formed in the mounting section 27b. The distal end section 24b of the shaft section 24a is inserted into the plate hole 27a. The shaft sections 24a are inserted into the plate holes 27a and mounted on the mounting sections 27b. The connecting plates 27 rotate together with the rotation of the shaft sections 24a.

[0046] An extension section 27c is formed on the mounting section 27b. The extension sections 27c extend towards the radially outer side of the nozzle ring 23. A distal end section 27d of the extension section 27c, on a side opposite the mounting section 27b, is arranged between the pair of projection sections 25e and 25f. That is, the distal end section 27d of the connecting plate 27 faces the first projection section 25e and the second projection section 25f in the circumferential direction of the main body section 25b. In other words, the first projection section 25e and the second projection section 25f are spaced apart from each other in the circumferential direction of the main body section 25b of the drive ring 25 and face each other such that the connecting plate 27 is arranged in a sandwich-like configuration.In this state, a distance between one pair of the first projection section 25e and the second projection section 25f is defined such that it is slightly larger than the width of the distal end section 27d. In other words, a space is formed between the distal end section 27d and each of the pair of the first projection section 25e and the second projection section 25f in a state in which the distal end section 27d is positioned between the one pair of the first projection section 25e and the second projection section 25f.

[0047] Fig. Figure 4 shows a perspective view illustrating a state after the nozzle propulsion mechanism 20 has been assembled. As described above, the pins 22 are inserted into the plate pin holes 21b (see Figure 4). Fig. 2) and the ring pin holes 23f are inserted. Both ends of the pins 22 are crimped, and the plate 21, the pins 22, and the nozzle ring 23 are subsequently assembled together. The drive hole 25a (inner circumferential surface) of the drive ring 25 and the cylindrical section 23c (outer circumferential surface) of the nozzle ring 23 face each other radially. The drive ring 25 is held by the nozzle ring 23 so that it is rotatable. An axial movement of the drive ring 25 is restricted by the guide pins 26. That is, the guide pins 26 serve to prevent axial loosening of the drive ring 25. The nozzle vanes 24 are positioned at the distance, i.e., the gap (namely the flow channel “x”) between the plate 21 and the nozzle ring 23. The shaft sections 24a are axially supported by the shaft holes 23j of the nozzle ring 23. The connecting plate 27 is mounted on the distal end section 24b of the shaft section 24a.

[0048] In this state, a drive connection plate (not shown) is arranged between the third projecting section 25g and the fourth projecting section 25h of the drive ring 25. The drive connection plate is a plate-shaped element with substantially the same external shape as the connection plate 27. A distal end section of the drive connection plate is arranged between the third projecting section 25g and the fourth projecting section 25h, similar to the connection plate 27. A drive shaft is inserted into a base end section of the drive connection plate. The base end section of the drive connection plate is positioned on the radially inner side of the drive ring 25 with respect to the distal end section. The drive connection plate is rotated by receiving a force from an actuator (not shown) via the drive shaft.The distal end section of the drive connection plate is then brought into contact with the third projecting section 25g and the fourth projecting section 25h, pressing these sections together. This transmits a circumferential force to the drive ring 25, which has the third projecting section 25g and the fourth projecting section 25h. In this way, the actuator force is transmitted to the drive ring 25 (the third projecting section 25g and the fourth projecting section 25h). As a result, the drive ring 25 rotates (slides) while supported by the cylindrical section 23c of the nozzle ring 23.

[0049] As described above, the distal end section 27d of the connecting plate 27 is positioned between a pair of projection sections 25e and 25f of the drive ring 25. Therefore, when the drive ring 25 rotates, the distal end section 27d is brought into contact with either the first projection section 25e or the second projection section 25f. The distal end section 27d is pressed in the direction of rotation. The connecting plates 27 then rotate (pivot) about an axial center of the shaft sections 24a. As a result, the shaft sections 24a mounted on the connecting plates 27 rotate. In this way, the plurality of nozzle vanes 24 rotate concurrently with the shaft sections 24a. The flow channel width of the flow channel “x” thus changes.

[0050] In Fig. 5(a) is a section with a dashed line made up of Fig. 1 shown. In Fig. 5(b) is a section with a dashed line with a point from Fig. 1 shown.

[0051] As this is in Fig. As shown in Figure 5(a), at least part of the main body 23b of the nozzle ring 23 is positioned on the inside of the turbine housing 4. A projecting wall section 4a is formed on the turbine housing 4. The projecting wall section 4a extends towards the inside in the radial direction of the shaft 8. The main body 23b of the nozzle ring 23 has the outer circumferential surface 23d, which extends on a left side (side of the nozzle vane 24) in Fig. 5(a) is formed with respect to the projecting section 23e. The outer circumferential surface 23d has a smaller diameter than the projecting section (projecting section) 23e. A gap Sa is formed between the projecting wall section 4a and the outer circumferential surface 23d.

[0052] The projecting section 23e is held in place by the projecting wall section 4a from the side of the connecting plate 27 (side of the bearing housing 2). The wall section 4b is a section of the turbine housing 4 that is positioned on the radially outer side of the projecting section 23e. A gap Sb is formed between the wall section 4b and the outer circumferential surface of the projecting section 23e.

[0053] Furthermore, a wave-hole projection 23k is formed on the inner circumferential surface of the annular hole 23a of the nozzle ring 23. The wave-hole projection 23k projects radially inwards. The wave-hole projection 23k is located on a left side (the side of the nozzle vane 24) of Fig. 5(a) of the inner circumferential surface of the annular hole 23a is positioned. The annular hole projection 23k is positioned on the radially outer side with respect to the impeller main body 9b, on which the vanes 9a are provided to be mounted. A gap Sc is defined between the shaft hole projection 23k and the impeller main body 9b.

[0054] A wall section 2b is a section of the bearing housing 2 positioned on the side of the rear face 9c of the impeller main body 9b. The annular projection 2c protrudes from the side of the rear face 9c. A housing hole 2d is open in the annular projection 2c. The shaft 8 is inserted into the housing hole 2d.

[0055] A leaf spring 28 is a ring-shaped element. An insertion hole 28a is formed in the leaf spring 28. The ring-shaped projection 2c (shaft 8) is inserted into the insertion hole 28a. The leaf spring 28 is arranged between the rear surface 9c of the turbine impeller 9 and the wall section 2b of the bearing housing 2.

[0056] An outer contact section 28b of the leaf spring 28 on a radially outer side is brought into contact with the shaft hole projection 23k of the nozzle ring 23 from the side of the connecting plate 27. Furthermore, an inner contact section 28c of the leaf spring 28 on its radially inner side, relative to the outer contact section 28b, is brought into contact with the wall section 2b of the bearing housing 2 from one side of the turbine impeller 9. The leaf spring 28 is supported by the bearing housing 2 by the inner contact section 28c. For example, the inner contact section 28c of the leaf spring 28 sits on an outer circumferential section of the annular projection 2c.

[0057] The leaf spring 28 is designed to exert an elastic force on the nozzle ring 23 from the outer contact section 28b. The leaf spring 28 is designed to move the nozzle ring 23 to the left side. Fig. 5(a) (in a direction from the connecting plates 27 to the nozzle vanes 24) presses.

[0058] Furthermore, the outer contact section 28b is pressed against the shaft hole projection 23k. The inner contact section 28c is pressed against the wall section 2b. In this way, the leaf spring 28 seals the two contact sections. The leaf spring 28 also provides a heat shielding function to prevent heat from the exhaust gas from being transferred to the side of the radial bearing 27.

[0059] The projecting section 23e of the nozzle ring 23 is pressed against the projecting wall section 4a of the turbine housing 4 by the leaf spring 28. As a result, the nozzle ring 23 is positioned (held) inside the bearing housing 2 and the turbine housing 4.

[0060] Furthermore, the pressure on one side of the flow channel “x” is increased by the exhaust gas. If the pressure on the side of the connecting plate 27 is exceptionally low, a difference will arise between the pressure at the nozzle vanes 24 from the left side and the pressure at the other side. Fig. 5(a) acts, and a pressure acting on the shaft sections 24a from the right side is high. The nozzle vanes 24 are pressed to the right side (side of the connecting plate 27). As a result, a gap between the nozzle vanes 24 and the plate 21 becomes large. Consequently, the function of the nozzle vanes 24 may deteriorate.

[0061] As this is in Fig. As shown in Figure 5(a), the spaces Sa and Sb are not in communication with each other at a location where the projecting section 23e of the nozzle ring 23 and a projecting wall section 4a of the turbine housing 4 are in contact. That is, even if the pressure difference exists, the exhaust gas does not flow through there. Thus, as shown in Fig. 5(b) shows the counterbore grooves 23g formed on the nozzle ring 23.

[0062] Fig. Figure 6 shows an explanatory view illustrating the counterbore grooves 23g. Fig. Figure 6 shows the plate 21, the pins 22, and the nozzle ring 23 of the nozzle drive mechanism 20 extracted and illustrated. As shown in Fig. As shown in Figure 6, the counterbore grooves 23g of the nozzle ring 23 are formed on the side of the cylindrical section 23c of the main body 23b. The ring pin hole 23f is open in the counterbore groove 23g. The pins 22 are inserted into the ring pin holes 23f. Parts of the projecting section 23e are cut out through the counterbore grooves 23g.

[0063] Therefore, as is stated in Fig. As shown in Figure 5(b), the two spaces Sa and Sb communicate with each other. The exhaust gas flows from the flow channel “x” to the side of the connecting plate 27. As a result, the pressure difference between the side of the flow channel “x” and the side of the connecting plate 27 decreases. The pressure force of the nozzle vanes 24 towards the side of the connecting plate 27 is thus suppressed.

[0064] Furthermore, the thickness of a section of the main body 23b of the nozzle ring 23, through which the ring pin holes 23f pass, is approximately equal to the thickness of the plate 21 as a result of forming the counterbore grooves 23g. In this way, the axial lengths of both end sections 22a and 22b of the pin 22, which have a smaller diameter than the larger diameter section 22c, are designed to be equal to each other. Therefore, even if the directions of the two end sections 22a and 22b of the pin 22 are reversed, the pin 22 can still be inserted into the plate 21 and the nozzle ring 23. Consequently, the work efficiency increases.

[0065] Fig. Figure 7(a) shows a front view of the drive ring 25. Fig. Figure 7(b) shows a perspective view of the drive ring 25. As shown in the Fig. 7(a) and Fig. As shown in Figure 7(b), a plurality of cutout sections 25j are formed on the main body section 25b of the drive ring 25. The cutout section 25j is positioned between a pair of the first projection section 25e and the second projection section 25f. That is, a gap Sd is formed between the pair of the first projection section 25e and the second projection section 25f (between the sections). The gap Sd extends through the main body section 25b in the axial direction.

[0066] The third projecting section 25g is configured such that it extends to the second projecting section 25f in the circumferential direction of the main body section 25b. Furthermore, in the present invention, the third projecting section 25g extends to the radially inner side with respect to the second projecting section 25f. That is, a shoulder 25fg is formed between the second projecting section 25f and the third projecting section 25g such that it extends to the second projecting section 25f. The shoulder 25fg extends in the radial direction. Similarly, the fourth projecting section 25h is configured such that it extends to the first projecting section 25e in the circumferential direction of the main body section 25b. Furthermore, in the present invention, the fourth projecting section 25h extends to the radially inner side with respect to the first projecting section 25e.This means that a shoulder surface 25eh is formed between the first projection section 25e and the fourth projection section 25h such that it extends to the first projection section 25e. The shoulder surface 25ef extends in the radial direction. The above describes the case in which the third projection section 25g and the second projection section 25f are formed in such a way that they extend to each other, and the fourth projection section 25h and the first projection section 25e are formed in such a way that they extend to each other. However, a cutout may be formed between the third projection section 25g and the second projection section 25f. Furthermore, a cutout may be formed between the fourth projection section 25h and the first projection section 25e.

[0067] Furthermore, the cutout section 25j is also formed between the third projection section 25g and the fourth projection section 25h. The gap Sd is formed between the third projection section 25g and the fourth projection section 25h. The gap Sd extends through the main body section 25b in the axial direction.

[0068] Fig. Figure 8 shows a section-like enlarged view of the drive ring 25. As this is shown in Fig. As shown in Figure 8, a base end section 25e1 of the first projection section 25e projects radially outward from the outer circumferential surface 25d of the drive ring 25. Furthermore, a distal end section 25e2 of the first projection 25e is located on an upper side in Fig. 8 with respect to an end surface 25k of the main body section 25b of the drive ring 25 on the upper side (side of the connecting plate 27) of Fig. 8. A distal end surface 25e3 of the distal end section 25e2 faces the radially inner side of the main body section 25b. The distal end surface 25e3 is positioned on the radially inner side of the main body section 25b with respect to the outer circumferential surface 25d (second outer circumferential surface 25d2 described below).

[0069] Furthermore, the first projection segment 25e has a curved segment 25e4. The curved segment 25e4 is positioned between the base end segment 25e1 and the distal end segment 25e2. The curved segment 25e4 extends from the base end segment 25e1 to an upper side in Fig. 8 bent (the side of the connecting plate 27 in the direction of the central axis (an axial direction of the shaft 8) of the main body section 25b of the drive ring 25, the side of the bearing housing 2 in the thickness direction of the drive ring 25, and the side facing away from the nozzle ring 23). The bent section 25e4 is bent towards the distal end section 25e2 towards the radially inner side of the main body section 25b.

[0070] The base end section 25e1 and the distal end section 25e2 are spaced apart from each other in the axial direction. A gap Se is formed between the base end section 25e1 and the distal end section 25e2. The base end sections 25e1 are formed on the outer circumference of the main body section 25b of the drive ring 25. The base end section 25e1 projects radially. The distal end section 25e2 overlaps the base end section 25e1 in the axial direction. The base end section 25e1 and the distal end section 25e2 are connected to each other by the curved section 25e4.

[0071] Similarly, a base end section 25f1 of the second projection section 25f projects radially outward from the outer circumferential surface 25d of the drive ring 25. A distal end section 25f2 of the second projection section 25f is located on the upper side in Fig. 8 is positioned with respect to the end surface 25k of the main body section 25b of the drive ring 25. A distal end surface 25f3 of the distal end section 25f2 faces the radially inner side of the main body section 25b.

[0072] Furthermore, the second projection section 25f has a curved section 25f4. The curved section 25f4 is positioned between the base end section 25f1 and the distal end section 25f2. The curved section 25f4 extends from the base end section 25f1 to the upper side in Fig. 8 bent (the side of the connecting plate 27 in the direction of the central axis (the axial direction of the shaft 8) of the main body section 25 of the drive ring 25). The bent section 25f4 is bent towards the distal end section 25f2 towards the radially inner side of the main body section 25b.

[0073] The base end section 25f1 and the distal end section 25f2 are spaced apart from each other in the axial direction. That is, a gap Sf is formed between the base end section 25f1 and the distal end section 25f2.

[0074] Furthermore, a section of the outer circumferential surface 25d of the drive ring 25, positioned between the pair of first projection sections 25e and second projection sections 25f, is designated as the "first outer circumferential surface 25d1". Additionally, sections of the outer circumferential surface 25d of the drive ring 25 positioned on the outside (outside of) the pair of first projection sections 25e and second projection sections 25f are each designated as the "second outer circumferential surface 25d2". The first outer circumferential surface 25d1 is positioned on the radially inner side of the main body section 25b with respect to the second outer circumferential surface 25d2. That is, the cutout section 25j extends to the radially inner side of the main body section 25b with respect to the second outer circumferential surface 25d2.

[0075] A first connecting section 25m is a section that connects both the base end section 25e1 of the first projecting section 25e (first projection section) and the base end section 25f1 of the second projection section 25f and the first outer circumferential surface 25d1. The first connecting section 25m has a curved surface shape. The center of curvature of the first connecting section 25m is located on the side that is spaced away (distanced) from the main body section 25b (radially outer side) with respect to the first outer circumferential surface 25d1, in a section that includes the first outer circumferential surface 25d1, and is perpendicular to the axial direction. The first connecting section 25m rises radially outward from the first outer circumferential surface 25d1 in the section that includes the first outer circumferential surface 25d1 and is perpendicular to the axial direction.

[0076] A second connecting section 25n is a section that connects both the base end section 25e1 of the first projecting section 25e and the base end section 25f1 of the second projecting section 25f and the second outer circumferential surface 25d2. The second connecting section 25n has a curved surface shape. The center of curvature of the second connecting section 25n is positioned on a side spaced (away) from the main body section 25b (radially outer side) with respect to the second outer circumferential surface 25d2, in a section that includes the second outer circumferential surface 25d2, and is perpendicular to the axial direction. The second connecting section 25n rises radially outward from the second outer circumferential surface 25d2 in the section that includes the second outer circumferential surface 25d2 and is perpendicular to the axial direction.

[0077] Furthermore, as is stated in the Fig. 7(a) and Fig. As shown in Figure 7(b), the third projection section 25g and the fourth projection section 25h each have the same shape as the first projection section 25e and the second projection section 25f. That is, the third projection section 25g has a base end section 25g1, a distal end section 25g2, a distal end surface 25g3, and a curved section 25g4 similar to the first projection section 25e and the second projection section 25f. The fourth projection section 25h has a base end section 25h1, a distal end section 25h2, a distal end surface 25h3, and a curved section 25h4 similar to the first projection section 25e and the second projection section 25f.

[0078] The distal end surface 25g3 of the third projection section 25g and the distal end surface 25h3 of the fourth projection section 25h are positioned on the radially inner side with respect to the distal end surfaces 25e3 and 25f3 of the first projection section 25e and the second projection section 25f.

[0079] Furthermore, a third connecting section 25p is a section that connects both the base end section 25g1 of the third projection section 25g and the base end section 25h1 of the fourth projection section 25h and the second outer circumferential surface 25d2. The third connecting section 25p has a curved surface shape.

[0080] Fig. Figure 9(a) shows a view illustrating a first projection section Aa and a second projection section Ab of a drive ring A of a comparative example from a radially outer side of a main body section Ac. Fig. Figure 9(b) shows a view illustrating the first projection section 25e and the second projection section 25f of the drive ring 25 of the present embodiment from the radially outer side of the main body section 25b.

[0081] As this is in Fig. As shown in Figure 9(a), the cutout section 25j is not formed between the first projection section Aa and the second projection section Ab in the drive ring A of the comparison example. If, for example, the first projection section Aa presses the distal end section Ba of a connecting plate B, a stress concentration results at a boundary section (as a circle of a dashed line in Fig. 9(a) shown) between the first projection section Aa and an end surface Ad. Similarly, when the second projection section Ab presses the distal end section Ba of the connecting plate B, a stress concentration occurs at a boundary section between the second projection section Ab and the end surface Ad.

[0082] As this is in Fig. As shown in Figure 9(b), the cutout sections 25j are formed in the drive ring 25 of this embodiment. Therefore, when the first projecting section 25e or the second projecting section 25f presses the distal end section 27d of the connecting plate 27, the stress concentration can be reduced.

[0083] Furthermore, the cutout section 25j between the third projection section 25g and the fourth projection section 25h is similar to the section between the first projection section 25e and the second projection section 25f. This reduces any stress concentration that might occur when the third projection section 25g or the fourth projection section 25h is pressed through the connecting plate.

[0084] Fig. Figure 10(a) shows a front view of a drive ring 125 according to the invention. Fig. Figure 10(b) shows a perspective view of the drive ring 125 according to the invention. As this is shown in Fig. 10(a) and in Fig. As shown in Figure 10(b), a plurality of cutout sections 125j are formed in a main body section 125b of a drive ring 125, similar to the embodiment mentioned above. The cutout section 125j is positioned between a pair of a first projecting section 125e and a second projecting section 125f (between the sections). That is, the gap Sd is formed between the pair of first projecting sections 125e and second projecting sections 125f (between the sections). The gap Sd extends through the main body section 125b in the axial direction.

[0085] A third projecting section 125g is configured such that it is spaced apart (distanced) from the second projecting section 125f in the circumferential direction of the main body section 125b. Similarly, a fourth projecting section 125h is configured such that it is spaced apart (distanced) from the first projecting section 125e in the circumferential direction of the main body section 125b. The third projecting section 125g and the fourth projecting section 125h extend to the radially inner side of the main body section 125b with respect to the first projecting section 125e and the second projecting section 125f. Furthermore, the cutout section 125j between the third projecting section 125g and the fourth projecting section 125h is configured similarly to the section between the first projecting section 125e and the second projecting section 125f.This means that the space Sd between the third projection section 125g and the fourth projection section 125h is formed similarly to the section between the pair of projection sections 125e and 125f. The space Sd extends through the main body section 125b in the axial direction.

[0086] Furthermore, slot sections 125q are formed in the main body section 125b. The slot section 125q is positioned on the radially inner side of each of the pair consisting of the first projection section 125e and the second projection section 125f. The slot section 125q extends through the main body section 125b in the axial direction. Similarly, the slot section 125q is formed on the radially inner side of each of the third projection section 125g and the fourth projection section 125h of the main body section 125b. These slot sections 125q are configured to extend to (be open at) the cutout sections 125j. For example, the space Sd can be a space formed by the cutout section 125j and the slot sections 125q.In the present configuration, for example, a step or the like can be formed at a boundary section between an inner circumferential surface of the cutout section 125j and an inner wall surface of the slot section 125q. The boundary section between the inner wall surface of the cutout section 125j and the inner wall surface of the slot section 125q can be a continuous flat surface.

[0087] Fig. Figure 11 shows a section-like enlarged view of the drive ring 125 according to the invention. As this is shown in Fig. As shown in Figure 11, a base end section 125e1 of the first projection section 125e is bent from the main body section 125b. A distal end section 125e2 of the first projection section 125e projects to an upper side in Fig. 11 (the side of the connecting plate 27 in the direction of the central axis (the axial direction of the shaft 8) of the main body section 125b of the drive ring 125, the side of the bearing housing 2 in the thickness direction of the drive ring 125, and the side facing away from the nozzle ring 23) with respect to an end face 125k. Similarly, the base end section 125f1 of the second projecting section 125f is bent from the main body section 125b. A distal end section 125f2 of the second projecting section 125f projects to the upper side in Fig. 11 in relation to the end surface 125k.

[0088] Connecting sections between the first projection section 125e and the main body section 125b each have a curved surface shape on both a side of the end surface 125k and a side of the cutout section 125j. Similarly, connecting sections between the second projection section 125f and the main body section 125b each have a curved surface shape on both the side of the end surface 125k and the side of the cutout section 125j. In addition, each of the end sections 125q1 of the slot section 125q has a curved surface shape in the circumferential direction of the main body section 125b. The center of curvature of the end section 125q1 of the slot section 125q is positioned on the side furthest from the drive ring 125 with respect to the end section 125q1.

[0089] In this setup, the final section 125q1 can also be as described below. That is, in Fig. 10(a) is defined as an angle value between a connecting line (reference line) linking a center position of the main body section 125b in the radial direction and a center position of the slot section 125q in the circumferential direction, and a connecting line linking the center position of the main body section 125b in the radial direction and an arbitrarily chosen position of the slot section 125q in the circumferential direction. For example, the angle value is defined as a positive value in the clockwise direction. Fig. Figure 10(a) shows the angle as a negative value in the counterclockwise direction. In this setup, the end segments 125q1 are located at a position with a maximum angle value and at a position with a minimum angle value.

[0090] Furthermore, as this has in Fig. As shown in Figure 10(a), the end section 125q1 has an arc shape with a central angle of 90 degrees in the front view of the drive ring 125. However, the central angle of the arc shape of the end section 125q1 can also be equal to or greater than 90 degrees, or less than 90 degrees. Furthermore, an inner wall surface with a straight line shape extending radially inward from the inner wall surface with the arc shape can be formed on the end section 125q1. In this case, a second inner wall surface with an arc shape can be formed on a section between the inner wall surface with the straight line shape and the first projection section 125e and the second projection section 125f, respectively, in the radial direction. The center of curvature of the second inner wall surface with the arc shape is positioned on the midface of the slot section 125q in the circumferential direction with respect to the second inner wall surface with the arc shape.As described above, the stress concentration can be reduced if at least the inner wall surfaces of the connecting sections of the end section 125q1, which is connected to the first projecting section 125e and the second projecting section 125f, each have the arc shape in the front view of the drive ring 125.

[0091] Furthermore, although a detailed illustration is omitted, the third projecting section 125g and the fourth projecting section 125h have shapes similar to those of the first projecting section 125e and the second projecting section 125f. That is, a base end section of the third projecting section 125g is bent away from the main body section 125b. A distal end section of the third projecting section 125g projects towards the side of the connecting plate 27 (the side of the bearing housing 2 in the thickness direction of the drive ring 125, and the side facing away from the nozzle ring 23) in the direction of the central axis (the axial direction of the shaft 8) of the main body section 125b of the drive ring 125 with respect to the end face 125k. Similarly, a base end section of the fourth projecting section 125h is bent away from the main body section 125b.A distal end section of the fourth projection section 125h projects to the side of the connecting plate 27 (the side of the bearing housing 2 in the thickness direction of the drive ring 125, and the side facing away from the nozzle ring 23) in the direction of the central axis (the axial direction of the shaft 8) of the main body section 125b of the drive ring 125 with respect to the end surface 125k (see . Fig. 10(b)).

[0092] Furthermore, in the first modified example, the cutout sections 125j on the main body section 125b are designed similarly to the embodiment mentioned above. Therefore, the stress concentration can be reduced when the first projecting section 125e or the second projecting section 125f presses against the distal end section 27d of the connecting plate 27. Similarly, the stress concentration that occurs when the third projecting section 125g or the fourth projecting section 125h is pressed through the drive connecting plate can be reduced.

[0093] Fig. Figure 12(a) shows a front view of a drive ring 225 of a modified example. Fig. Figure 12(b) shows a perspective view of the drive ring of the modified example. As this is shown in the Fig. 12(a) and Fig. As shown in Figure 12(b), a plurality of cutout sections 225j are formed on a main body section 225b of the drive ring 225, similar to the embodiment mentioned above and the first modified example. The cutout section 225j is positioned between a pair of a first projecting section 225e and a second projecting section 225f (between the sections). That is, the gap Sd is formed between the pair of first projecting sections 225e and second projecting sections 225f (between the sections). The gap Sd extends through the main body section 225b in the axial direction.

[0094] The third projecting section 225g is configured such that it is spaced (distanced from) (points away from) the second projecting section 225f in the circumferential direction of the main body section 225b. Similarly, the fourth projecting section 225h is configured such that it is spaced (distanced from) (points away from) the first projecting section 225e in the circumferential direction of the main body section 225b. The third projecting section 225g and the fourth projecting section 225h extend towards the radially inner side of the main body section 225b with respect to the first projecting section 225e and the second projecting section 225f. Furthermore, the cutout section 225j is also formed between the third lead section 225g and the fourth lead section 225h in a similar way to the section between the first lead section 225e and the second lead section 225f.

[0095] Furthermore, curved surface sections 225q are formed on the main body section 225b. The curved surface section 225q is positioned on an inner wall surface of the cutout section 225j on a radially inner side of the main body section 225b. Moreover, the center of curvature of the curved surface section 225q is positioned on a radially outer side of the main body section 225b with respect to the curved surface section 225q.

[0096] Fig. Figure 13(a) shows a section-like enlarged view of the drive ring 225 before the section sections 225j of the modification example are formed. Fig. Figure 13(b) shows a section-like enlarged view of the drive ring 225 after the section sections 225j of the modified example have been formed. As this is shown in Fig. As shown in Figure 13(a), the main body section 225b extends between the first projection section 225e and the second projection section 225f before the cutout sections 225j are formed. The main body section 225b extends between the third projection section 225g and the fourth projection section 225h. In other words, the main body section 225b has a ring-like shape. The plurality of first projection sections 225e and second projection sections 225f, the third projection section 225g, and the fourth projection section 225h are arranged to be spaced apart from each other circumferentially and axially, while the main body section 225b serves as a base section.For example, the cutout sections 225j and the curved surface sections 225q are formed by applying such machining as cutting on the main body section 225b with such a shape.

[0097] Furthermore, in the second modified example, the cutout sections 225j on the main body section 225b are designed similarly to the embodiment mentioned above and the first modified example. Therefore, the stress concentration can be reduced when the first projecting section 225e or the second projecting section 225f presses against the distal end section 27d of the connecting plate 27. Similarly, the stress concentration that occurs when the third projecting section 225g or the fourth projecting section 225h is pressed through the drive connecting plate can be reduced. In addition, in the second modified example, the curved surface section 225q is formed on an inner wall surface of the cutout section 225j. Therefore, the stress concentration is further reduced.

[0098] An embodiment of the present invention is described above with reference to the accompanying drawings; however, it need not be said that the present invention is not limited to the embodiment mentioned above. It is obvious that those skilled in the art may think of various modifications and variations within the scope of the claims, and such examples are naturally intended to fall within the technical scope of the present invention.

[0099] For example, in one of the aforementioned examples, the case is described in which the first projecting section 25e and the second projecting section 25f project radially outwards from the outer circumferential surface 25d of the drive ring 25. The case is described in which the first projecting section 25e and the second projecting section 25f are bent towards the side of the connecting plate 27 (the side of the bearing housing 2 in the thickness direction of the drive ring 25, and the side facing away from the nozzle ring 23) in the direction of the central axis (the axial direction of the shaft 8) of the main body section 25b of the drive ring 25.In this case, the projection heights of the first projection sections 25e and the second projection sections 25f to the side of the connecting plate 27 (the side of the bearing housing 2 in the thickness direction of the drive ring 25, and the side facing away from the nozzle ring 23) of the main body section 25b of the drive ring 25 in the direction of the central axis (the axial direction of the shaft 8) can be designed by the gaps Se and Sf independently of the plate thickness of the main body section 25b in the axial direction. For example, the projection heights of the first projection section 25e and the second projection section 25f can be ensured to be greater than the plate thickness of the main body section 25b in the axial direction. That is, large contact areas of the first projection section 25e and the second projection section 25f on the connecting plate 25 can be ensured regardless of the plate thickness.Therefore, the strength against the load can be increased at the first projection sections 25e and the second projection sections 25f of the connecting plates 27.

[0100] Furthermore, the second outer circumferential surface 25d2 is positioned on the radially inner side of the main body section 25b with respect to the first projecting sections 25e and the second projecting sections 25f. Therefore, the weight can be reduced compared to a case where the second outer circumferential surface 25d2 extends to radial positions that are the same as those of the first projecting sections 25e and the second projecting sections 25f. Moreover, in the first and second modified examples, similar to the embodiment mentioned above, the second outer circumferential surfaces 125d2 and 225d2 can be cut out such that they are located on the radially inner side with respect to the first projecting sections 125e and 225e and with respect to the second projecting sections 125f and 225f, respectively.

[0101] Furthermore, the first projecting sections 25e and the second projecting sections 25f of the aforementioned embodiment can easily be formed, for example, by flanging or folding. This reduces costs. In this case, if the gaps Se and Sf are enlarged, deformation of the contact surfaces of the first projecting sections 25e and the second projecting sections 25f on the connecting plates 27 can be avoided.

[0102] Furthermore, in the example mentioned above, the first outer circumferential surfaces 25d1 of the drive ring 25 are positioned on the radially inner side with respect to the second outer circumferential surfaces 25d2. In this case, a large radius of curvature of the first connecting section 25m can be ensured, thereby reducing stress concentration. However, the first outer circumferential surfaces 25d1 can have the same radial position as the second outer circumferential surfaces 25d2, or they can be positioned on the radially outer side with respect to the second outer circumferential surfaces 25d2. Moreover, the first connecting sections 25m are not strictly necessary. The base end section 25e1 and the first outer circumferential surface 25d1 can be directly connected to each other.However, the stress concentration in the base end section 25e1 on the side of the first outer circumferential surface 25d1 can be reduced by forming the first connecting section 25m.

[0103] Furthermore, the second outer circumferential surfaces 25d2 can be positioned on the radially inner side with respect to the positions specified in the Fig. 7(a), Fig. 7(b) and Fig. Figure 8 shows that in this case, a large radius of curvature of the second connecting section 25n can be ensured, thereby reducing the stress concentration. However, the second connecting sections 25n are not strictly necessary. The base end section 25e1 and the second outer circumferential surface 25d2 can be directly connected. However, the stress concentration in the base end section 25e1 on the side of the second outer circumferential surface 25d2 can be reduced by forming the second connecting section 25n.

[0104] Furthermore, the modified example according to the invention describes the case in which the slotted sections 125q are formed. If, for example, the first projecting sections 125e and the second projecting sections 125f are formed by pressing, stress concentration during machining can be reduced by the slotted sections 125q. In addition, the cost of the drive ring 125 can be reduced by pressing. However, the method for machining the drive ring 125 is not limited to pressing and can, for example, be forging. In this case, the slotted sections 125q are not required. Moreover, in the cases of pressing and forging, the contact surfaces of the first projecting sections 125e and the second projecting sections 125 on the connecting plates 27 can be formed with high surface accuracy.

[0105] Furthermore, the modified example describes the case in which the curved surface sections 225q are formed on the inner wall surfaces of the cutout sections 225j. However, the curved surface sections 225q are not strictly necessary.

[0106] Furthermore, the example mentioned above describes the case in which the distal end surfaces 25g3 of the third projecting sections 25g are positioned on the radially inner side with respect to the distal end sections 25e3 and 25f3 of the first projecting sections 25e and the second projecting sections 25f. Similarly, the case is described in which the distal end surfaces 25h3 of the fourth projecting sections 25h are positioned on the radially inner side with respect to the distal end sections 25e3 and 25f3 of the first projecting sections 25e and the second projecting sections 25f. In addition, the modified example according to the invention describes the case in which the third projecting sections 125g extend to the radially inner side of the main body section 125b with respect to the first projecting sections 125e and the second projecting sections 125f.Similarly, the case is described in which the fourth projection sections 125h extend to the radially inner side of the main body section 125b with respect to the first projection sections 125e and the second projection sections 125f. Furthermore, in the modified example, the case is described in which the third projection sections 225g extend to the radially inner side of the main body section 225b with respect to the first projection sections 225e and the second projection sections 225f. Similarly, the case is described in which the fourth projection sections 225h extend to the radially inner side of the main body section 225b with respect to the first projection sections 225e and the second projection sections 225f.In these cases, for example, if a movable area of ​​the drive connection plate is high, a disengagement (disengagement) between the third projection sections 25g, 125g and 225g and the fourth projection sections 25h, 125h and 225h and the drive connection plate may be less likely to occur.

[0107] However, the distal end faces 25g3 of the third projection sections 25g can be located at the same radial positions as—or they can be located on the radially outer side with respect to—the distal end faces 25e3 and 25f3 of the first projection sections 25e and the second projection sections 25f. Similarly, the distal end faces 25h3 of the fourth projection sections 25h can be located at the same radial positions as—or they can be located on the radially outer side with respect to—the distal end faces 25e3 and 25f3 of the first projection sections 25e and the second projection sections 25f. Furthermore, the third projection sections 125g can extend radially to the same positions as those of the first projection sections 125e and the second projection sections 125f.Furthermore, the first lead sections 125e and the second lead sections 125f can extend to the radially inner side with respect to the third lead sections 125g. Similarly, the fourth lead sections 125h can extend radially to the same positions as those of the first lead sections 125e and the second lead sections 125f. Furthermore, the first lead sections 125e and the second lead sections 125f can extend radially to the radially inner side with respect to the fourth lead sections 125h. Furthermore, the third lead sections 225g can extend radially to the same positions as those of the first lead sections 225e and the second lead sections 225f.Furthermore, the first lead sections 225e and the second lead sections 225f can extend to the radially inner side with respect to the third lead sections 225g. Similarly, the fourth lead sections 225h can extend radially to the same positions as those of the first lead sections 225e and the second lead sections 225f. Additionally, the first lead sections 225e and the second lead sections 225f can extend to the radially inner side with respect to the fourth lead sections 225h. Industrial applicability

[0108] The present invention can be applied to a variable-capacity turbocharger (variable displacement) which has connecting plates on which nozzle vanes are mounted. Reference symbol list C Variable displacement turbocharger 23 nozzle ring 23j shaft hole 24 nozzle blades 24a Wave section 25 Drive ring 25b Main body section 25d outer perimeter area 25d1 first outer circumferential surface 25d2 second outer circumferential surface 25th first lead section 25e1 Base end section 25f second lead section 25f1 Base end section 25 years old, excerpt 25m first connecting section 25n second connecting section 27 Connecting plate 125 drive ring 125b Main body section 125d2 second outer circumferential surface 125e ​​first lead section 125e1 Base end section 125f second lead section 125f1 Base end section 125j excerpt 225 drive ring 225b Main body section 225d2 second outer circumferential surface 225e first lead section 225f second lead section 225j excerpt

Claims

[1] Variable capacity turbocharger (C) with: a drive ring (125) with a main body section (125b) which has a ring-like shape; a section (125j) that is formed in an outer circumferential surface (125d) of the main body section (125b); a first projecting section (125e) and a second projecting section (125f) formed in the cutout section (125j) and projecting in a circumferential direction of the main body section (125b) and bent towards a central axis, wherein the first projecting section (125e) and the second projecting section (125f) are spaced apart from each other in the circumferential direction of the main body section (125b) such that a connecting plate (27) is arranged in a sandwich-like manner, on which a nozzle vane (24) is mounted; and a slot section (125q) which is positioned on a radially inner side of the first projection section (125e) and the second projection section (125f). [2] Variable capacity turbocharger according to claim 1, further comprising a nozzle ring (23) having a shaft hole (23j) constructed in such a way as to axially support a shaft section (24a) which connects the nozzle vane (24) and the connecting plate (27) and is constructed in such a way as to support the main body section (125b) of the drive ring (125). [3] Variable capacity turbocharger according to claim 1, wherein distal end sections (125e2, 125f2) of the first projection section (125e) and the second projection section (125f) project to one side of the connecting plate (27) in the direction of the central axis. [4] Variable capacity turbocharger according to claim 1, wherein end sections (125q1) of the slot section (125q) have a curved shape in the circumferential direction.

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