Variable geometry turbochargers and assembly methods for variable geometry turbochargers

Abstract

This variable geometry turbocharger is equipped with: a turbine wheel; a variable nozzle device; a first housing having a worm-like flow path; a second housing which, between the first housing and the second housing, forms a receiving space for receiving the turbine wheel and the variable nozzle device and which has a through-hole for connecting the receiving space to the outside of the second housing; and a drive force transmission device configured to transmit drive force from an actuator located outside the second housing to the variable nozzle device.The drive force transmission device comprises: a control arm having an engagement part that engages with a drive force introduction part of the variable nozzle device in the receiving space and having a rotating shaft section that is inserted through the through-hole and partially protrudes to the outside of the second housing; and a control lever that is arranged outside the second housing and has a fastening part that is attached to the rotating shaft section of the control arm by connecting it.

Description

Technical field

[0001] The present disclosure relates to a variable geometry turbocharger and an assembly method for a variable geometry turbocharger. State of the art

[0002] A variable geometry turbine, which incorporates a variable nozzle device that changes the blade angle of a nozzle blade, is known as a turbocharger (supercharger) that supercharges the intake air of an internal combustion engine (machine) by using energy from the exhaust gas of the internal combustion engine (see, for example, PTL 1). In the variable geometry turbine, several nozzle blades are aligned circumferentially around a turbine wheel in an exhaust gas flow path to convey the exhaust gas from a screw-type flow path of the turbine to the turbine wheel, and the blade angles of the nozzle blades are changed externally by an actuator. In this way, the cross-sectional area (flow path between adjacent nozzle blades) of the exhaust gas flow path can be adjusted. The variable geometry turbine adapts the cross-sectional area of ​​the exhaust gas flow path.In this way, the variable geometry turbine improves a charging effect by changing the flow velocity or pressure of the exhaust gas directed to the turbine wheel. List of citations from patent literature

[0003] [PTL 1] US Patent No. 8,684,678 Summary of the invention: Technical problem

[0004] In a drive force transmission device that transmits a drive force from the actuator to the nozzle blade, as described in Fig. Figure 5 shows a rotating shaft section penetrating an inner and outer surface of a housing, and an engagement plate that transmits the driving force to the variable nozzle device inside the housing, attached by welding. In this case, it is difficult to compensate for a failure in any component forming the variable nozzle device or the driving force transmission device, or for an assembly error that occurs when each component is assembled. Therefore, it is necessary to design the variable nozzle device or the driving force transmission device of the turbocharger taking the occurrence of these failures into account in advance. Consequently, one degree of freedom in the design of these devices is reduced, and there is a possibility that one operating range will decrease when designing the variable nozzle device.

[0005] In view of the circumstances described above, at least one embodiment of the present disclosure aims to provide a variable geometry turbocharger and an assembly method for a variable geometry turbocharger that can suppress a reduction in the operating range of a variable nozzle device. Solution to the problem

[0006] According to at least one embodiment of the present disclosure, a variable geometry turbocharger is provided, comprising a turbine wheel, a first housing containing a screw flow path, a variable nozzle device forming a gas flow path from the screw flow path to the turbine wheel and configured to adjust the flow of a gas flowing through the gas flow path, a second housing connected to the first housing and forming a receiving space for receiving the turbine wheel and the variable nozzle device between the second housing and the first housing, the second housing containing a through-hole that allows the receiving space and an outer surface of the second housing to communicate with each other, and a drive force transmission device configured to transmit a drive force from an actuator located outside the second housing.The drive force transmission device comprises a control arm, which includes an engagement section that engages a drive force introduction unit of the variable nozzle device in the receiving space, and a rotating shaft section that is inserted into the through-hole and partially projects to the outside of the second housing, and a control lever that is located outside the second housing and includes a mounting target section that is attached to the rotating shaft section of the control arm by connecting it.

[0007] According to at least one embodiment of the present disclosure, an assembly method for a variable geometry turbocharger is provided, comprising a turbine wheel, a first housing containing a screw flow path, a variable nozzle device forming a gas flow path from the screw flow path to the turbine wheel and configured to adjust the flow of a gas flowing through the gas flow path, a second housing connected to the first housing and forming a receiving space for receiving the turbine wheel and the variable nozzle device between the second housing and the first housing, the second housing containing a through-hole that allows the receiving space and an outer surface of the second housing to communicate with each other, and a drive force transmission device configured to transmit a drive force from an actuator,The drive force transmission device includes a control arm comprising an engagement section that engages a drive force introduction unit of the variable nozzle device in the receiving space, and a rotating shaft section that is inserted into the through-hole and partially protrudes to the outside of the second housing, and a control lever that is located outside the second housing and includes a mounting target section that is attached to the rotating shaft section of the control arm by connecting it. In the assembly method for a variable geometry turbocharger, the method includes a control arm insertion step of inserting the rotating shaft section of the control arm into the through-hole, causing the rotating shaft section to partially protrude to the outside of the second housing.a control arm engagement step of bringing the engagement section of the control arm into engagement with the drive force introduction unit of the variable nozzle device after the control arm engagement step, a housing connection step of connecting the first housing and the second housing after the control arm engagement step, and a control lever fastening step of fastening the fastening target section of the control lever to the rotating shaft section of the control arm by connecting after the housing connection step. Advantageous effects of the invention

[0008] According to at least one embodiment of the present disclosure, a variable geometry turbocharger and an assembly method for a variable geometry turbocharger are provided which can suppress a reduction in the operating range of a variable nozzle device. Brief description of the drawings Fig. Figure 1 is a schematic cross-sectional view along an axis of a variable geometry turbocharger according to an embodiment of the present disclosure. Fig. Figure 2 is a schematic view when a variable nozzle device and a drive force transmission device of the turbocharger with variable geometry according to the embodiment of the present disclosure are viewed from one side in an axial direction. Fig. Figure 3 is a schematic cross-sectional view along the axis in a vicinity of the drive force transmission device of the variable geometry turbocharger according to the embodiment of the present disclosure. Fig. Figure 4 is a flowchart showing an example of an assembly method for a variable geometry turbocharger according to an embodiment of the present disclosure. Fig. Figure 5 is a schematic cross-sectional view along an axis in the environment of a drive force transmission device of a variable geometry turbocharger according to a comparative example. Fig. Figure 6 is a schematic cross-sectional view along the axis in the vicinity of the drive force transmission device of the variable geometry turbocharger according to the embodiment of the present disclosure. Fig. Figure 7 is a schematic cross-sectional view along the axis in the vicinity of the drive force transmission device of the variable geometry turbocharger according to the embodiment of the present disclosure. Description of embodiments

[0009] Some embodiments of the present disclosure are described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of components described as embodiments or shown in the drawings are not intended to limit the scope of protection of the present disclosure and are merely examples used to describe the present disclosure. (Turbocharger)

[0010] Fig. Figure 1 is a schematic cross-sectional view along an axis LA of a variable-geometry turbocharger 1 according to an embodiment of the present disclosure. For example, the variable-geometry turbocharger 1 according to the present disclosure can be applied to a turbocharger (supercharger) for automotive, marine, or industrial applications (for example, for shore power generation). As shown in Fig. As shown in Figure 1, the turbocharger 1, according to some embodiments, comprises at least one turbine rotor 20, a first housing (turbine housing) 3, a second housing (bearing housing) 4, a variable nozzle device 5, and a drive force transmission device 6. In the embodiment shown, the turbocharger 1 further comprises a centrifugal impeller 11, a third housing (compressor housing) 12, and a bearing 13. (turbine rotor)

[0011] As in Fig. As shown in Figure 1, the turbine rotor 20 includes a turbine shaft 21 extending along the axis LA of the turbine rotor 20, and a turbine wheel 2 located on one side (right side in the drawing) of the turbine shaft 21. The impeller 11 is attached to the other side (left side in the drawing) of the turbine shaft 21. (Battery and cartridge)

[0012] The bearing 13 is configured to be received in the second housing 4 between the impeller 11 and the turbine wheel 2, such that it rotatably supports the turbine shaft 21. The second housing 4 includes a bearing support section 14 that supports the bearing 13 radially from an outer side. In the present disclosure, a configuration in which the turbine rotor 20, the impeller 11, and the bearing 13 are attached to the second housing 4 of the turbocharger 1 is defined as a cartridge.

[0013] In the following, a direction of extension of the axis LA of the turbine rotor 20 is referred to as an axial direction of the turbine rotor 20, a direction perpendicular to the axis LA is referred to as a radial direction of the turbine rotor 20, and a circumferential direction around the axis LA is referred to as a circumferential direction of the turbine rotor 20. In the present disclosure, the axial direction, the radial direction, and the circumferential direction of the turbine rotor 20 can each simply be referred to as the axial direction, the radial direction, and the circumferential direction. In the axial direction of the turbine rotor 20, one side (right side in Fig. 1), on which the turbine wheel 2 is located in relation to the impeller 11, is defined as a front, and a side (side opposite the front, left side in Fig. 1), on which the impeller 11 is located in relation to the turbine wheel 2, is defined as a rear side. In the present disclosure, the description “along a certain direction” includes not only a specific direction, but also a direction inclined in relation to the specific direction within a range of ± 15°. (turbine wheel)

[0014] The turbine wheel 2 comprises a hub 22, which has a substantially conical trapezoidal shape, and several turbine blades 23, which are provided on an outer circumferential surface of the hub 22. The several turbine blades 23 are each spaced apart from one another in the circumferential direction around the axis LA. The turbine wheel 2 is designed to be rotatable about the axis LA integrally with the turbine shaft 21. The turbine wheel 2 is configured to guide an exhaust gas introduced from the outside in the radial direction of the turbine wheel 2 to the front face along the axial direction of the turbine wheel 2. In the embodiment shown, the turbine wheel 2 comprises an open-type impeller that does not include an annular element surrounding an outer circumference of the several turbine blades 23. (Balance bike)

[0015] The impeller 11 comprises a hub 111, which has a substantially conical trapezoidal shape, and several compressor blades 112, which are provided on an outer circumferential surface of the hub 111. The several compressor blades 112 are arranged at intervals of each other in the circumferential direction around the axis LA. The impeller 11 is mounted so that it is integrally rotatable with the turbine shaft 21 about the axis LA. The impeller 11 is configured to guide a combustion gas (for example, air), which is a gas supplied as an oxygen-containing gas for combustion in an internal combustion engine (machine) (not shown), introduced from the rear along the axial direction of the impeller 11, outwards in the radial direction of the impeller 11. In the embodiment shown, the impeller 11 contains an open-type impeller that does not contain an annular element surrounding an outer circumference of the multiple compressor blades 112. (First case and third case)

[0016] The first housing 3 is connected to the second housing 4 and is configured to hold the turbine wheel 2 so that it can rotate between the first housing 3 and the second housing 4. The third housing 12 is connected to the second housing 4 and is configured to hold the impeller 11 so that it can rotate between the third housing 12 and the second housing 4. The second housing 4 is positioned between the first housing 3 and the third housing 12 and is connected to both the first housing 3 and the third housing 12 via a fastening element (not shown), such as a bolt.

[0017] The first housing 3 is provided with a spiral flow path 31 for guiding the exhaust gas discharged from the internal combustion engine to the turbine wheel 2 and an exhaust gas outlet flow path 32 for discharged the exhaust gas passing through the turbine wheel 2 to the outside of the first housing 3 (turbocharger 1). In other words, the first housing 3 contains the spiral flow path 31 and the exhaust gas outlet flow path 32. The spiral flow path 31 is located on the outer side in the radial direction of the turbine wheel 2 such that it surrounds one circumference of the turbine wheel 2 and contains a spiral flow path extending along the circumferential direction. The exhaust gas outlet flow path 32 extends towards the front side along the axial direction.

[0018] The second housing 4 forms a receiving space 33 for receiving the turbine wheel 2 and the variable nozzle device 5 between the first housing 3 and the second housing 4. The first housing 3 and the second housing 4 are connected to each other, thereby forming the receiving space 33, which connects the screw flow path 31 and the exhaust gas outlet flow path 32. The turbine wheel 2 and the variable nozzle device 5 are arranged in the receiving space 33, which is formed on an inner side in the radial direction with respect to the screw flow path 31.

[0019] The variable nozzle device 5 is configured to form a gas flow path 33A from the screw flow path 31 to the turbine wheel 2 and to adjust the flow of the gas flowing through the gas flow path 33A. The gas flow path 33A is located between the screw flow path 31 and the turbine wheel 2 in the radial direction of the turbine wheel 2 such that it surrounds the outer surface of the turbine wheel 2 in the radial direction of the turbine wheel 2. The gas flow path 33A is a section of the receiving chamber 33 and is formed on an outer circumferential side of the receiving chamber 33 with respect to a receiving section for the turbine wheel 2. The exhaust gas is guided from the screw flow path 31 to the turbine wheel 2 via the gas flow path 33A.

[0020] The exhaust gas generated by combustion in the internal combustion engine and discharged from the engine is guided to the turbine wheel 2 via the screw flow path 31 and the gas flow path 33A. The turbocharger 1 is configured to rotate the turbine wheel 2 by utilizing the energy of the exhaust gas directed to it. The impeller 11 is coaxially connected to the turbine wheel 2 via the turbine shaft 21. Therefore, the impeller 11 is driven to rotate about the axis LA in conjunction with the rotation of the turbine wheel 2. The exhaust gas used to drive the turbine wheel 2 is discharged to the outside of the first housing 3 via the exhaust outlet flow path 32.

[0021] The turbocharger 1 is configured as follows. Air (combustion gas) is drawn into the third housing 12 by rotating the impeller 11 around the axis LA, the air is compressed, and the compressed air is supplied to the internal combustion engine.

[0022] A gas inlet flow path 121 and a screw flow path 122 are formed in the third housing 12. The gas inlet flow path 121 is a flow path for drawing in air (combustion gas) from the outside of the third housing 12 and for guiding the drawn-in air to the impeller 11. The gas inlet flow path 121 extends along the axial direction of the impeller 11 and is located on one side (rear side) of the impeller 11 in the axial direction. Since the impeller 11 is driven by rotation, air is drawn from the outside of the third housing 12 into the gas inlet flow path 121, and the drawn-in air flows in the gas inlet flow path 121 towards the impeller 11 and is guided to it.

[0023] The screw-type flow path 122 is positioned externally in the radial direction of the impeller 11 such that it surrounds one circumference of the impeller 11 and contains a spiral flow path extending along the circumference of the impeller 11. The air flowing through and compressed by the impeller 11 is directed to the screw-type flow path 122. The compressed air flowing through the screw-type flow path 122 is then directed to the internal combustion engine. (Variable nozzle device)

[0024] Fig. Figure 2 is a schematic view when the variable nozzle device 5 and the drive force transmission device 6 of the turbocharger 1 are viewed from one side (rear side) in the axial direction according to the embodiment of the present disclosure. In some embodiments, as shown in Fig. 1 and Fig. 2 shown, the variable nozzle device 5, a drive force introduction unit 51, a nozzle holder 52, several nozzle vanes 53, a drive ring 54 and several lever plates 55. (Nozzle holder)

[0025] The nozzle holder 52 forms a gas flow path 33A between the nozzle holder 52 and the further element 10. The nozzle holder 52 is located on a rear side with respect to the gas flow path 33A, and the further element 10 is located on a front side with respect to the gas flow path 33A. Hereinafter, a direction of extension of an axis LB of the nozzle holder 52 (variable nozzle device 5) is referred to as the axial direction of the variable nozzle device 5, a direction perpendicular to the axis LB is referred to as the radial direction of the variable nozzle device 5, and the circumferential direction around the axis LB is referred to as the circumferential direction of the variable nozzle device 5. The direction of extension of the axis LB is a direction along the direction of extension of the axis LA.

[0026] The nozzle holder 52 includes an annular plate arranged on an outer circumferential side of the turbine wheel 2 and extending along the circumferential direction of the variable nozzle device 5. The nozzle holder 52 has an annular flow path surface 521 on the holder side, which faces the gas flow path 33A on one side of the nozzle holder 52 in a thickness direction, i.e., on the front side. The nozzle holder 52 includes an annular rear surface 522 on the other side (the side opposite the holder-side flow path surface 521) of the nozzle holder 52 in the thickness direction, i.e., on the back side. (Nozzle plate)

[0027] In the embodiment shown, the variable nozzle device 5 further includes a nozzle plate 56, which is the further element 10 described above, as shown in Fig. Figure 1 shows the nozzle plate 56, which includes an annular plate extending along the circumferential direction of the variable nozzle device 5. The nozzle plate 56 includes an annular plate-side flow path surface 561, which faces the gas flow path 33A on one side of the nozzle plate 56 in the thickness direction, i.e., on the rear side. The plate-side flow path surface 561 is arranged such that it faces the holder-side flow path surface 521, with a gap between them, and forms the gas flow path 33A between the plate-side flow path surface 561 and the holder-side flow path surface 521.In some further embodiments, the variable nozzle device 5 may not include the nozzle plate 56, and the first housing 3, which is the further element 10, may include a flow path surface that forms the gas flow path 33A between the plate-side flow path surface 561 and the holder-side flow path surface 521. (Nozzle holder)

[0028] In the embodiment shown, the variable nozzle device 5 includes, as in Fig. Figure 1 shows several nozzle holders 57, which support the nozzle holder 52 and the nozzle plate 56 in a state in which they are separated from each other. Each of the several nozzle holders 57 is arranged externally in the radial direction of the variable nozzle device 5 with respect to the several variable nozzle blades 53.

[0029] The mounting-side rear surface 522 of the nozzle holder 52 is configured to form a rear space 33B between the first housing 3 and the second housing 4. The rear space 33B is a section of the receiving space 33 and is formed on a side opposite the gas flow path 33A via the nozzle holder 52. (Nozzle blade)

[0030] Each of the multiple nozzle blades 53 is arranged in the gas flow path 33A and is supported by the nozzle holder 52 such that it can pivot about any center of rotation RC. The multiple nozzle blades 53 are arranged at intervals in the circumferential direction of the variable nozzle device 5. (Drive ring)

[0031] The drive ring 54 is arranged in the rear space 33B, and the drive force introduction unit 51 is attached to the drive ring 54. The drive ring 54 is designed to pivot about the axis LB with respect to the nozzle holder 52 by a drive force transmitted via the drive force introduction unit 51. The drive ring 54 includes an annular body that extends along the circumferential direction of the variable nozzle device 5. The drive ring 54 includes locating sections 541 at several locations along the circumferential direction of the variable nozzle device 5. (Lever plate)

[0032] The variable nozzle assembly 5 includes the same number of lever plates 55 as nozzle blades 53. Each of the multiple lever plates 55 includes a blade attachment section 551, which is attached to one of the multiple nozzle blades 53, and a fitting section 552, which is adapted to one of the multiple target fitting sections 541 of the drive ring 54. Each of the multiple lever plates 55 is arranged in the rear space 33B. The blade attachment section 551, which is provided on one side of the lever plate 55, is attached to the corresponding nozzle blade 53, and the fitting section 552, which is provided on the other side of the lever plate 55, is adapted to the corresponding target fitting section 541. Each of the multiple lever plates 55 is configured to change a blade angle of the nozzle blade 53 attached to the blade attachment section 551 in conjunction with the pivoting of the drive ring 54 about the axis LB.

[0033] At the in Fig. In the embodiment shown in Figure 2, each of the multiple fitting target sections 541 includes a groove section formed in an outer circumferential edge section of the drive ring 54, and each of the multiple fitting sections 552 is received in the corresponding groove section and is loosely fitted to the groove section.

[0034] The nozzle holder 52 has several through-holes 523 that penetrate the flow path surface 521 and the rear surface 522 on the holder side. The multiple through-holes 523 are arranged at intervals along the circumference of the variable nozzle device 5. The nozzle holder 52 has the same number of through-holes 523 as the nozzle blades 53. Each of the multiple lever plates 55 is inserted into the corresponding through-hole 523.

[0035] When the drive ring 54 is rotated circumferentially to one side of the variable nozzle device 5, the circumferentially adjacent nozzle blades 53 move (rotate) in a direction in which they are separated from each other, and the cross-sectional area of ​​the gas flow path 33A between the nozzle blades 53 increases. Furthermore, when the drive ring 54 is rotated circumferentially to the other side of the variable nozzle device 5, the circumferentially adjacent nozzle blades 53 move (pivot) in a direction in which they are closer together, and the cross-sectional area of ​​the gas flow path 33A between the nozzle blades 53 decreases.

[0036] The variable nozzle device 5 transmits the driving force from an actuator 60 via the drive ring 54 and the multiple lever plates 55 to the multiple nozzle blades 53. This causes the multiple nozzle blades 53 to pivot about their respective centers of rotation RC to change their blade angles. In this way, the cross-sectional area of ​​the gas flow path 33A can be adjusted. The turbocharger 1 can change the flow velocity or pressure (inlet pressure) of the exhaust gas directed to the turbine wheel 2 and the flow velocity or pressure (outlet pressure) of the exhaust gas passing through the turbine wheel 2 by causing the variable nozzle device 5 to increase or decrease the cross-sectional area of ​​the gas flow path 33A. In this way, the boost pressure of the turbocharger 1 can be controlled. (Drive force transmission device)

[0037] Fig. Figure 3 is a schematic cross-sectional view along the axis LA in the vicinity of the drive force transmission device 6 of the turbocharger 1 according to the embodiment of the present disclosure. As in Fig. As shown in Figure 1, the drive force transmission device 6 is configured to transmit the drive force from the actuator 60, which is located outside the second housing 4, to the variable nozzle device 5. The drive force transmission device 6 includes at least one control arm 7 and one control lever 8. (Control arm)

[0038] As in Fig. 1 and Fig. As shown in Figure 2, the control arm 7 includes an engagement section 71 that engages in the drive force introduction unit 51 of the variable nozzle device 5 in the rear space 33B (receiving space 33) described above, and a rotary shaft section 72 that is inserted into a through-hole 41 that penetrates the inside and outside of the second housing 4, with a section of the rotary shaft section 72 projecting to the outside of the second housing 4.

[0039] In the embodiment shown, as in Fig. Figure 1 shows the control arm 7 having a connecting section 42 on the side of the second housing, which extends from a front end section of the second housing 4 along the radial direction outwards and is connected to the first housing 3, and a connecting section 45 on the side of the third housing, which extends from a rear end section of the second housing 4 along the radial direction outwards and is connected to the third housing 12.

[0040] The connecting section 42 on the side of the second housing has a surface 43 that faces the rear space 33B on one side of the connecting section 42 on the side of the second housing in the thickness direction, i.e., on the front, and the other surface 44 that faces the outer space 47 of the second housing 4 on the other side of the connecting section 42 on the side of the second housing in the thickness direction, i.e., on the rear. The connecting section 45 on the side of the third housing has a surface 46 that faces the outer space 47 of the second housing 4 on one side of the connecting section 45 on the side of the third housing in the thickness direction, i.e., on the front. One surface 46 faces the other surface 44 via the outer space 47.The through-hole 41 extends along a direction parallel to the axial direction and penetrates one surface 43 and the other surface 44 of the connecting section 42 on the side of the second housing. The rear chamber 33B communicates with the outer chamber 47 via the through-hole 41.

[0041] The rotating shaft section 72 is formed in a rod shape extending along an axis LD of the rotating shaft section 72, and an engagement plate 73, containing the engagement section 71, is attached to one side of the rotating shaft section 72 in the direction of extension. The engagement plate 73 extends in a direction that intersects (perpendicular to, in the example shown) the axis LD, and the engagement section 71 is formed on a side opposite the side to which the rotating shaft section 72 is attached. The rotating shaft section 72 and the engagement plate 73 are formed integrally. The other side of the rotating shaft section 72 in the direction of extension includes a projection section 72A that projects into the external space 47. (Control lever)

[0042] The control lever 8 is located outside the second housing 4. The control lever 8 includes a mounting target section 81, which is attached to the projecting section 72A of the rotating shaft section 72 by connecting it. The control lever 8 includes a long plate 82 extending along a longitudinal direction, and the mounting target section 81 is attached to one side of the long plate 82 in the longitudinal direction. The mounting target section 81 and the long plate 82 are integrally formed. In the control lever 8, the mounting target section 81 is attached to the projecting section 72A by connecting it. In this way, the control lever 8, together with the control arm 7, is pivotable about the axis LD.

[0043] The drive force transmission device 6 includes a connection mechanism that transmits the drive force from a drive unit 601 of the actuator 60 to the control arm 8. In the illustrated embodiment, the other side of the long plate 82 is connected to one side of a first connecting element 62, so that it can be rotated about an axis LE via a pivot mechanism section 61, which includes a connecting pin or the like. The other side of the first connecting element 62 is connected to the other side of a second connecting element 64, which has one side that is attached to the drive unit 601 of the actuator 60 such that it can be pivoted about an axis LF via a pivot mechanism section 63, which includes a connecting pin or the like. (Assembly procedure for turbochargers)

[0044] Fig. Figure 4 is a flowchart showing an example of an assembly method 100 for the variable geometry turbocharger 1 according to the embodiment of the present disclosure. The assembly method 100 for the variable geometry turbocharger 1 according to some embodiments is the assembly method for the turbocharger 1 described above. As in Fig. As shown in Figure 4, the assembly method 100 for the turbocharger 1 includes at least one control arm insertion step S1, one control arm engagement step S2, one housing connection step S3 and one control lever fastening step S4.

[0045] In control arm insertion step S1, the rotating shaft section 72 of the control arm 7 is inserted into the through-hole 41, and a section of the rotating shaft section 72 is caused to protrude towards the outside of the second housing 4. Control arm insertion step S1 is performed on the cartridge of the turbocharger 1.

[0046] In the control arm engagement step S2, following the control arm insertion step S1, the engagement section 71 of the control arm 7 engages the drive force introduction unit 51 of the variable nozzle device 5. In the control arm engagement step S2, the variable nozzle device 5 is attached to the cartridge of the turbocharger 1.

[0047] In the housing connection step S3, the first housing 3 and the second housing 4 are connected to each other after the control arm engagement step S2. In the control lever fastening step S4, after the housing connection step S3, the fastening target section 81 of the control lever 8 is attached to the rotary shaft section 72 of the control arm 7 by connecting it. (Turbocharger according to comparison example)

[0048] Fig. Figure 5 is a schematic cross-sectional view along the LA axis in the vicinity of a drive force transmission device 06 of a variable geometry turbocharger 01 according to a comparative example. As in Fig. As shown in Figure 5, the drive force transmission device 06 comprises an engagement plate 07 and a crank element 08. The engagement plate 07 is provided with an engagement section 071 and a through-hole 072, which engage with the drive force introduction unit 51 of the variable nozzle device 5. The crank element 08 integrally forms a rotating shaft section 081, which is inserted into the through-hole 41, and a long plate 082, which is attached to a section of the rotating shaft section 081 that projects to the outside of the second housing 4. In the rotating shaft section 081, one side of the rotating shaft section 081 is inserted into the through-hole 072, and the rotating shaft section 081 and the engagement plate 07 are welded together in a weld section W3. In this way, the rotating shaft section 081 is attached to the engagement plate 07.

[0049] In the case of turbocharger 01 according to the comparative example, after the variable nozzle device 5 and the first housing 3 have been attached to the cartridge of turbocharger 1, the rotating shaft section 081 and the engagement plate 07 cannot be welded. Therefore, in turbocharger 01, after the rotating shaft section 081 and the engagement plate 07 have been welded, the variable nozzle device 5 and the first housing 3 are attached to the cartridge of turbocharger 1.

[0050] In the turbocharger 1 of the present disclosure, after the variable nozzle device 5 and the first housing 3 are attached to the cartridge of the turbocharger 1, the control arm 7 and the control lever 8 can be secured by connecting them. In this case, a defect in any component forming the variable nozzle device 5 or the drive force transmission device 6, or an assembly error that occurs when each component is assembled, can be compensated for when the control arm 7 and the control lever 8 are secured by connecting them. In contrast, in the turbocharger 01 according to the comparative example, since the defect in any component or the assembly error cannot be compensated for, it is necessary to design the variable nozzle device 5 and the drive force transmission device 6 of the turbocharger 01 in advance, taking into account the occurrence of these defects.Consequently, one degree of freedom is reduced in the design of these devices, and there is a possibility that one operating range decreases in the design of the variable nozzle device 5.

[0051] Therefore, according to the configuration (method) described above, after attaching the variable nozzle device 5 and the first housing 3 to the second housing 4, the control arm 7 and the control lever 8 can be secured by connecting them. In this case, any defect in either component forming the variable nozzle device 5 or the drive force transmission device 6, or any assembly error occurring during the assembly of each component, can be compensated for by securing the control arm 7 and the control lever 8 by connecting them. Furthermore, according to the configuration (method) described above, the degree of freedom in designing the variable nozzle device 5 or the drive force transmission device 6 can be improved compared to the turbocharger 01 in the comparative example.Therefore, it is possible to improve the wear resistance margin of the variable nozzle device 5 or the drive force transmission device 6, or to operate the variable nozzle device 5 or the drive force transmission device 6 with the actuator 60, which has a relatively low power output. Furthermore, according to the configuration (method) described above, a connecting section between the control arm 7 and the control lever 8 is provided on the outside (outer chamber 47) of the turbocharger 1 housing, where it operates at a relatively low temperature. In this way, the reliability of the turbocharger 1 can be improved in comparison to when the connecting section is provided on the inside (rear chamber 33B) of the turbocharger 1 housing, where it operates at a relatively high temperature.

[0052] As in Fig. As shown in Figure 4, the assembly method 100 for the turbocharger 1, according to some embodiments, further includes a control arm adjustment step S5, which involves adjusting the angle of the rotating shaft section 72 of the control arm 7 in the circumferential direction. The control arm adjustment step S5 is performed after the housing connection step S3 and before the control lever fastening step S4. In the control arm adjustment step S5, when the pressure (inlet pressure) of the exhaust gas introduced into the first housing 3 is set to a prescribed pressure, the angle of the rotating shaft section 72 in the circumferential direction is adjusted so that the pressure (outlet pressure) of the exhaust gas discharged from the first housing 3 has a prescribed value or falls within a prescribed range. The angle of the rotating shaft section 72 in the circumferential direction during the control arm adjustment step S5 is adjusted by rotating the projecting section 72A outside the second housing 4.

[0053] Actuator 60 is configured to change the operating angle of control lever 8 to an operating angle corresponding to an externally input instruction value. A prescribed instruction value is input into actuator 60, and the operating angle of control lever 8 is set to a prescribed operating angle. In control arm attachment step S4, control arm 7, where the inlet pressure is set to the prescribed pressure and the outlet pressure is at or within the prescribed range, is connected to control lever 8, which has the prescribed operating angle.In this case, the error of each component forming the variable nozzle device 5 or the drive force transmission device 6, or the assembly error that occurs when each component is assembled, can be effectively compensated when the control arm 7 and the control lever 8 are attached by connecting them.

[0054] Fig. 6 and Fig. Figure 7 are schematic cross-sectional views along the axis in the vicinity of the drive force transmission device 6 of the variable geometry turbocharger 1 according to the embodiment of the present disclosure. In the turbocharger 1 according to some embodiments, as shown in Fig. 3 and Fig. Figure 6 shows the fastening target section 81 described above being connected to the rotating shaft section 72 by welding or brazing.

[0055] At the in Fig. In the embodiment shown in Figure 3, the fastening target section 81 described above is connected to the rotating shaft section 72 by welding. In the embodiment shown in Figure 3, the fastening target section 81 is connected to the rotating shaft section 72 by welding. Fig. In the embodiment shown in Figure 3, the drive force transmission device 6 comprises a welded section W1, which welds together an end face on a side separated from the through-hole 41 of the mounting target section 81 and an outer circumferential surface of the projecting section 72A, and a welded section W2, which welds together an end face on a side adjacent to the through-hole 41 of the mounting target section 81 and the outer circumferential surface of the projecting section 72A. The drive force transmission device 6 may comprise only one of the welded sections W1 and W2.

[0056] At the in Fig. In the embodiment shown in 6, the fastening target section 81 described above is connected to the rotating shaft section 72 by soldering. In the embodiment shown in Fig. In the embodiment shown in Figure 6, the drive force transmission device 6 includes a soldering section BM for attaching an inner surface of the attachment target section 81 and an outer circumferential surface of the projection section 72A to each other via a soldering material by soldering.

[0057] According to the configuration described above, the mounting target section 81 and the rotating shaft section 72 are connected to each other by welding or brazing. Therefore, it is not necessary to provide a separate fastener or similar element to secure the mounting target section 81 and the rotating shaft section 72 together. Consequently, it is possible to avoid increasing the number of components of the variable nozzle device 5 or the drive force transmission device 6.

[0058] In the turbocharger 1 according to some embodiments, as in Fig. As shown in Figure 7, the fastening target section 81 described above is connected to the rotating shaft section 72 by crimping. In the Fig. In the embodiment shown in Figure 7, the fastening target section 81, which surrounds the rotating shaft section 72, includes a crimp area 812 which is deformed by receiving an external force F and is connected to the rotating shaft section 72 by crimping.

[0059] According to the configuration described above, the mounting target section 81 and the rotating shaft section 72 are connected to each other by crimping. Therefore, it is not necessary to provide a separate fastener or similar element for securing the mounting target section 81 and the rotating shaft section 72 together. This eliminates the need to increase the number of components of the variable nozzle device 5 or the drive force transmission device 6.

[0060] In the turbocharger 1 according to some embodiments, as shown in Fig. 3, Fig. 6 and Fig. Figure 7 shows the fastening target section 81 described above as a tubular section 81A having an inner circumferential surface 811 that surrounds an outer circumferential surface 721 of the rotating shaft 72, which projects to the outside of the second housing 4. The outer circumferential surface 721 and the inner circumferential surface 811 are formed in a circular contour shape.

[0061] According to the configuration described above, since the mounting target section 81 contains the tubular section 81A, the tubular section 81A is not limited when the rotating shaft section 72 has any angle in the circumferential direction. Therefore, it is easy to mount the tubular section 81A and the rotating shaft section 72 and adjust the angle in the circumferential direction.

[0062] In the turbocharger 1 according to some embodiments, as in Fig. Figure 7 shows a screw groove 811A, into which the rotating shaft section 72 of the control arm 7 is screwed, formed on the inner circumferential surface 811 of the tubular section 81A described above. A screw groove 721A, which is screwed into the screw groove 811A, is formed on the outer circumferential surface 721 of the projecting section 72A of the rotating shaft section 72.

[0063] According to the configuration described above, the screw groove 811A, into which the rotating shaft section 72 is screwed, is provided on the inner circumferential surface 811 of the tubular section 81A. This makes it easier to adjust the angle of the tubular section 81A and the rotating shaft section 72 in the circumferential direction. The screw grooves 811A and 721A can be located in the tubular section 81A or the rotating shaft section 72, which is in Fig. 3 and Fig. 6 is shown, be educated.

[0064] As in Fig. 3, Fig. 6 and Fig. As shown in Figure 7, the turbocharger 1, according to some embodiments, further comprises a sleeve 9 arranged between the through-hole 41 described above and the rotating shaft section 72 described above. The sleeve 9 is pressed into the through-hole 41 before the control arm insertion step S1. The surface roughness (for example, arithmetic mean roughness, maximum height, and ten-point mean roughness) of an inner surface of the sleeve 9 is less than the surface roughness of an inner surface of the through-hole 41.

[0065] According to the configuration described above, the sleeve 9 is arranged between the through-hole 41 and the rotating shaft section 72. In this way, it is possible to suppress any deviation of the axis LD of the rotating shaft section 72, and it is possible to reduce frictional loss when the rotating shaft section 72 rotates.

[0066] In the turbocharger 1 according to some embodiments, as shown in Fig. 1 and Fig. Figure 2 shows the variable nozzle device 5 and the drive ring 54, to which the nozzle holder 52, the multiple nozzle blades 53, the drive force introduction unit 51, and the multiple lever plates 55 are attached. In this case, the drive force is transmitted from the drive force transmission device 6 to the drive force introduction unit 51, which is attached to the drive ring 54. In this way, the blade angles of the multiple nozzle blades 53 can be changed via the drive ring 54 and the multiple lever plates 55.

[0067] In the turbocharger 1 according to some embodiments, as shown in Fig.Figure 2 shows the drive force introduction unit 51 having an engagement pin 51A attached to the drive ring 54, and the engagement section 71 containing the insert hole or insert groove 71A into which the engagement pin 51A is inserted.

[0068] According to the configuration described above, the control arm 7 is rotated by the drive force of the actuator 60 about the axis LD of the rotating shaft section 72. In this way, the engagement pin 51A can be moved through the insert hole or the insert groove 71A about the axis LB of the variable nozzle device 5.

[0069] In the present description, expressions of relative or absolute arrangement, such as "in a certain direction", "along a certain direction", "parallel", "perpendicular", "center", "concentric" or "coaxial", indicate not only the arrangement in a strict sense, but also a state in which the arrangement is shifted relatively by a tolerance or by an angle or distance to such an extent that the same function can be obtained.

[0070] For example, expressions that indicate things are in the same state, such as "identical", "equal" and "homogeneous", do not only indicate an equal state in a strict sense, but also a state in which a difference exists with a tolerance or to such an extent that the same function can be maintained.

[0071] Furthermore, in the present description, an expression of a shape, such as a rectangular shape and a cylindrical shape, indicates not only the rectangular shape and the cylindrical shape in a geometrically strict sense, but also an uneven section or a chamfered section within the area in which the same effect can be achieved.

[0072] Furthermore, in the present description, expressions such as "provided with", "contain" and "have" a configuration element are not exclusive expressions that exclude the presence of other configuration elements.

[0073] The present disclosure is not limited to the embodiments described above and also includes a form in which modifications are added to the embodiments described above, or a form in which the embodiments are suitably combined with one another.

[0074] For some of the embodiments described above, the content described is understood, for example, as follows. 1) According to at least one embodiment of the present disclosure, the variable geometry turbocharger (1) is provided, comprising the turbine wheel (2), the first housing (3) containing the screw flow path (31), the variable nozzle device (5) forming the gas flow path (33A) from the screw flow path (31) to the turbine wheel (2) and configured to adjust the flow of gas through the gas flow path (33A), the second housing (4) connected to the first housing (3) and forming a receiving space (33) for receiving the turbine wheel (2) and the variable nozzle device (5) between the first housing (3) and the second housing (4), the second housing (4) containing the through-hole (41) that allows the receiving space (33) and the outside of the second housing (4) to communicate with each other, and the drive force transmission device (6), which is configured to is configuredthat it transmits the driving force from the actuator (60), which is arranged outside the second housing (4), to the variable nozzle device (5). The driving force transmission device (6) includes the control arm (7), which includes the engagement section (71), which engages the driving force introduction unit (51) of the variable nozzle device (5) in the receiving space (33), and the rotating shaft section (72), which is inserted into the through-hole (41) and partially projects to the outside of the second housing (4), and the control lever (8), which is arranged outside the second housing (4) and includes the attachment target section (81), which is attached by connecting to the rotating shaft section (72) of the control arm (7).

[0075] According to the configuration described in 1) above, after the variable nozzle device (5) and the first housing (3) have been attached to the second housing (4), the control arm (7) and the control lever (8) can be secured by connecting them. In this case, any error in either component forming the variable nozzle device (5) or the drive force transmission device (6), or any assembly error that occurs during the assembly of each component, can be compensated for by securing the control arm (7) and the control lever (8) by connecting them. Furthermore, according to the configuration described in 1) above, compared to the turbocharger (01) in the comparative example, it is possible to improve the degree of freedom in designing the variable nozzle device (5) or the drive force transmission device (6).

[0076] 2) In some embodiments of the variable geometry turbocharger (1) according to 1), the mounting target section (81) is connected to the rotating shaft section (72) by welding or brazing.

[0077] According to the configuration of 2) above, the mounting target section (81) and the rotating shaft section (72) are connected by welding or brazing. In this way, it is not necessary to provide the fastener or the like separately for securing the mounting target section (81) and the rotating shaft section (72). Therefore, it is possible to reduce the number of components of the variable nozzle device (5) or the drive force transmission device (6).

[0078] 3) In some embodiments of the variable geometry turbocharger (1) according to 1), the mounting target section (81) is connected to the rotating shaft section (72) by crimping.

[0079] According to the configuration in 3) above, the mounting target section (81) and the rotating shaft section (72) are connected by crimping. Therefore, it is not necessary to provide a separate fastener or similar element for securing the mounting target section (81) and the rotating shaft section (72). This eliminates the need to increase the number of components for the variable nozzle device (5) or the drive force transmission device (6).

[0080] 4) In some embodiments of the variable geometry turbocharger (1) according to one of 1) to 3) above, the mounting target section (81) includes the tubular section (81A) which has the inner circumferential surface (811) that surrounds the outer circumferential surface (721) of the rotating shaft section (72) which projects to the outside of the second housing (4).

[0081] According to the configuration described in section 4) above, since the mounting target section (81) contains the tubular section (81A), if the rotating shaft section (72) has any angle in the circumferential direction, the tubular section (81A) has no limit. Therefore, it is easy to mount the tubular section (81A) and the rotating shaft section (72) and adjust the angle in the circumferential direction.

[0082] 5) In some embodiments of the variable geometry turbocharger (1) according to 4), a screw groove (811A) into which the rotating shaft section (72) of the control arm (7) is screwed is formed on the inner circumferential surface (811) of the tubular section (81A).

[0083] According to the configuration of 5) above, the screw groove (811A), into which the rotating shaft section (72) is screwed, is provided on the inner circumferential surface (811) of the tubular section (81A). In this way, it is easier to adjust the angle of the tubular section (81A) and the rotating shaft section (72) in the circumferential direction.

[0084] 6) In some embodiments, the variable geometry turbocharger (1) according to one of 1) to 5) above further comprises the sleeve (9) which is arranged between the through-hole (41) and the rotating shaft section (72).

[0085] According to the configuration in Figure 6) above, the sleeve (9) is arranged between the through-hole (41) and the rotating shaft section (72). In this way, it is possible to suppress the deviation of the axis (LD) of the rotating shaft section (72) and to reduce the frictional loss when the rotating shaft section (72) rotates.

[0086] 7) In some embodiments, the variable geometry turbocharger (1) according to one of 1) to 6) above includes the variable nozzle assembly (5) the nozzle holder (52), which forms the gas flow path (33A) between the nozzle holder (52) and the further element (10), the multiple nozzle vanes (53) which are mounted so that they are pivotable through the nozzle holder (52), the drive ring (54), which is provided so that it is pivotable about the axis of the nozzle holder (52) and includes the target sections (541) at the multiple locations along the circumferential direction, wherein the drive force introduction unit (51) is attached to the drive ring (54), and the multiple lever plates (55), each comprising the vane attachment section (551) attached to one of the multiple nozzle vanes (53) and the target section (552) attached to one of the multiple target sections (541). the drive ring (54) is adapted, included.

[0087] According to the configuration shown in Figure 7 above, the driving force is transmitted from the driving force transmission device (6) to the driving force introduction unit (51), which is attached to the drive ring (54). In this way, the blade angles of the multiple nozzle blades (53) can be changed via the drive ring (54) and the multiple lever plates (55).

[0088] 8) In some embodiments of the variable geometry turbocharger (1) according to 7), the drive force introduction unit (51) of the variable nozzle device (5) includes the engagement pin (51A) which is attached to the drive ring (54), and the engagement section (71) of the control arm (7) includes the insert hole or insert groove (71A) into which the engagement pin (51A) is inserted.

[0089] According to the configuration shown in Figure 8 above, the control arm (7) is rotated by the drive force from the actuator (60) about the axis (LD) of the rotating shaft section (72). In this way, the engagement pin (51A) can be moved through the insert hole or insert groove (71A) about the axis (LB) of the variable nozzle device (5).

[0090] 9) According to at least one embodiment of the present disclosure, the assembly method (100) for the variable geometry turbocharger (1) is provided, comprising the turbine wheel (2), the first housing (3) containing the screw flow path (31), the variable nozzle device (5) forming the gas flow path (33A) from the screw flow path (31) to the turbine wheel (2) and configured to adjust the flow of the gas flowing through the gas flow path (33A), the second housing (4) connected to the first housing (3) and forming the receiving space (33) for receiving the turbine wheel (2) and the variable nozzle device (4) between the second housing (4) and the first housing (3), wherein the second housing (4) includes the through-hole (41) that allows the receiving space (33) and the outside of the second housing (4) to communicate with each other, and the Drive force transmission device (6) configured such thatthat it transmits the driving force from the actuator (60), which is arranged outside the second housing (4), to the variable nozzle device (5). The driving force transmission device (6) includes the control arm (7), which includes the engagement section (71), which engages in the driving force introduction unit (51) of the variable nozzle device (5) in the receiving space (33), and the rotating shaft section (72), which is inserted into the through-hole (41) and partially projects to the outside of the second housing (4), and the control lever (8), which is arranged outside the second housing (4) and includes the attachment target section (81), which is attached by connecting to the rotating shaft section (72) of the control arm (7). In the assembly procedure (100) for the variable geometry turbocharger (1), the assembly procedure (100) comprises the control arm insertion step (S1) of inserting the rotating shaft section (72) of the control arm (7) into the through hole (41),so that the rotating shaft section (72) is caused to partially protrude to the outside of the second housing (4), the control arm engagement step (S2) of bringing the engagement section (71) of the control arm (7) into engagement with the drive force introduction unit (51) of the variable nozzle device (5) after the control arm insertion step (S1), the housing connection step (S3) of connecting the first housing (3) and the second housing (4) after the control arm engagement step (S2), and the control lever fastening step (S4) of fastening the fastening target section (81) of the control lever (8) to the rotating shaft section (72) of the control arm (7) by connecting after the housing connection step (S3).

[0091] According to the procedure described in 9) above, after the variable nozzle device (5) and the first housing (3) have been attached to the second housing (4), the control arm (7) and the control lever (8) can be secured by connecting them. In this case, the error of each component forming the variable nozzle device (5) or the drive force transmission device (6), or the assembly error that occurs when each component is assembled, can be compensated for when the control arm (7) and the control lever (8) are secured by connecting them. Furthermore, the turbocharger (1) assembled by the procedure described in 9) above can improve the degrees of freedom in designing the variable nozzle device (5) or the drive force transmission device (6) compared to the turbocharger (01) according to the comparative example. Reference symbol list 1.01 Variable geometry turbocharger 2 turbine wheel 3 first case 4 second case 5 variable nozzle device 6.06 Drive force transmission device 7 Control arm 8 control levers 9 sleeve 10 more elements 11 Balance bike 12 third case 13 warehouses 14 Bearing support section 20 turbine rotor 21 Turbine shaft 22 hub 23 turbine blades 31 Snail flow path 32 Exhaust gas outlet flow path 33 Recording Room 33A Gas flow path 33B rear room 41 Through hole 47 Outdoor space 51 Drive force introduction unit 51A Intervention pin 52 Nozzle holder 53 Nozzle blade 54 Drive ring 55 Lever plate 56 nozzle plate 57 nozzle holders 60 actuator 71 Intervention section 71A Insert slot 72 Rotary shaft section 72A Lead Section 73 Insertion plate 81 Mounting target section 81A tubular section 82 long record 100 assembly methods for variable geometry turbochargers BM soldering section F external force S1 Control arm insertion step S2 Control arm intervention step S3 Housing Connection Step S4 control lever mounting step S5 Control arm adjustment step W1, W2, W3 Welding section QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 8,684,678

[0003]

Claims

[1] Variable geometry turbocharger, comprising: a turbine wheel; a first shell containing a snail-shaped flow path; a variable nozzle device that forms a gas flow path from the screw flow path to the turbine wheel and is configured to adjust a flow of gas passing through the gas flow path; a second housing connected to the first housing and forming a receiving space for receiving the turbine wheel and the variable nozzle device between the second housing and the first housing, the second housing containing a through-hole that allows the receiving space and an outer surface of the second housing to communicate with each other; and a drive force transmission device configured to transmit a drive force from an actuator located outside the second housing to the variable nozzle device, the drive force transmission device includes: a control arm comprising an engagement section that engages in a drive force introduction unit of the variable nozzle device in the receiving space, and a rotary shaft section that is inserted into the through-hole and partially projects to the outside of the second housing, and a control lever located outside the second housing and containing a mounting target section which is attached by connecting to the rotating shaft section of the control arm. [2] Turbocharger with variable geometry according to claim 1, wherein the attachment target section is connected to the rotating shaft section by welding or brazing. [3] Turbocharger with variable geometry according to claim 1, wherein the mounting target section is connected to the rotating shaft section by crimping. [4] Turbocharger with variable geometry according to any one of claims 1 to 3, wherein the mounting target section includes a tubular section having an inner circumferential surface surrounding an outer circumferential surface of the rotating shaft section projecting to the outside of the second housing. [5] Turbocharger with variable geometry according to claim 4, wherein a screw groove into which the rotating shaft section of the control arm is screwed is formed on the inner circumferential surface of the tubular section. [6] Variable geometry turbocharger according to any one of claims 1 to 3, further comprising: a sleeve that is positioned between the through-hole and the rotating shaft section. [7] Variable geometry turbocharger according to any one of claims 1 to 3, wherein the variable nozzle device comprises: a nozzle holder that forms the gas flow path between the nozzle holder and the other element, several nozzle blades, which are mounted in such a way that they can swivel through the nozzle holder, a drive ring designed to be pivotable about an axis of the nozzle holder, and comprising target sections at several points along a circumferential direction, wherein the drive force introduction unit is attached to the drive ring, and several lever plates, each containing a blade mounting section that attaches to one of the several nozzle blades and a fitting section that is adapted to one of several of the fitting target sections of the drive ring. [8] Variable geometry turbocharger according to claim 7, wherein the drive force introduction unit of the variable nozzle device includes an engagement pin attached to the drive ring, and The engagement section of the control arm contains an insert hole or groove into which the engagement pin is inserted. [9] Assembly method for a variable geometry turbocharger comprising: a turbine wheel, a first shell containing a helical flow path, a variable nozzle device that forms a gas flow path from the screw flow path to the turbine wheel and is configured to adjust the flow of a gas passing through the gas flow path, a second housing connected to the first housing and forming a receiving space for receiving the turbine wheel and the variable nozzle device between the second housing and the first housing, wherein the second housing includes a through-hole that causes the receiving space and an outer surface of the second housing to communicate with each other, and a drive force transmission device configured to transmit a drive force from an actuator located outside the second housing to the variable nozzle device, the drive force transmission device comprising: a control arm comprising an engagement section that engages in a drive force introduction unit of the variable nozzle device in the receiving space, and a rotary shaft section that is inserted into the through-hole and partially projects to the outside of the second housing, and a control lever arranged outside the second housing and comprising a mounting target section which is attached to the rotating shaft section of the control arm by connecting, the assembly method for a variable geometry turbocharger includes: a control arm insertion step of inserting the rotating shaft section of the control arm into the through hole, so that the rotating shaft section is caused to partially protrude towards the outside of the second housing; a control arm engagement step of bringing the engagement section of the control arm into engagement with the drive force introduction unit of the variable nozzle device after the control arm insertion step; a housing connection step of connecting the first housing and the second housing after the control arm engagement step; and a control lever fastening step of fastening the fastening target section of the control lever to the rotating shaft section of the control arm by connecting after the housing connection step.

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