Variable nozzle assembly and variable capacity exhaust turbocharger

Abstract

This variable nozzle device comprises: a nozzle holder; a nozzle plate defining a nozzle flow path between the nozzle holder and the nozzle plate; a nozzle holder having a rod shape connecting the nozzle holder and the nozzle plate and containing a pair of large-diameter sections that are larger in diameter than the central part of a body section positioned between the nozzle holder and the nozzle plate, the large-diameter sections being located at both ends of the body section in the direction of extension therefrom; and a nozzle blade rotatably mounted by at least one of the nozzle holder and the nozzle plate and positioned further downstream of the nozzle flow path than the nozzle holder.A recess is formed in the nozzle holder from a flow path surface facing the nozzle flow path, and at least part of one of the pair of large diameter sections is accommodated in the recess.

Description

Technical field

[0001] The present disclosure relates to a variable nozzle device and an exhaust gas turbocharger of the variable capacity type, which includes the variable nozzle device. State of the art

[0002] In the prior art, a variable-capacity exhaust gas turbocharger is known as an exhaust gas turbocharger that charges the intake air of a machine by using energy from the machine's exhaust gas (see, for example, PTL 1). In the variable-capacity exhaust gas turbocharger, a variable nozzle device adjusts the cross-sectional area of ​​a nozzle flow path that conveys exhaust gas from a screw-type flow path of a turbine housing to a turbine wheel, so that the flow velocity or pressure of the exhaust gas conveyed to the turbine wheel is changed to enhance a charging effect. List of citations from patent literature

[0003] [PTL 1] Japanese Patent No. 6655755 Summary of the invention: Technical problem

[0004] PTL 1 discloses that a rod-shaped nozzle holder supports a nozzle support and a nozzle plate in a state in which they are separated from each other and a body section of the nozzle holder, which is located in a nozzle flow path, has a small diameter section at a central section in an extension direction of the nozzle holder and has large diameter sections at both end sections, wherein the large diameter sections have diameters that are larger than the diameter of the small diameter section.However, in a case where the nozzle holder has the body section having the shape where both end sections are thick, the flow of exhaust gas colliding with the nozzle blade may be distorted, leading to an increase in the cost of an actuator that rotates the nozzle blade or an increase in the load on a linkage system (for example, a drive ring or a blade lever) that transmits the drive of the actuator to the nozzle blade.

[0005] The present disclosure was made in view of the problems described above, and one objective of the present disclosure is to provide a variable nozzle device comprising a nozzle holder having a body section shaped such that both end sections are thick, and which is able to suppress distortion in the flow of exhaust gas colliding with a nozzle blade. Solution to the problem

[0006] To achieve the above objective, a variable nozzle device according to the present disclosure comprises a nozzle holder, a nozzle plate defining a nozzle flow path between the nozzle holder and the nozzle plate, a rod-shaped nozzle holder connecting the nozzle holder and the nozzle plate and comprising a pair of large-diameter sections provided at both ends in an extension direction in a body section located between the nozzle holder and the nozzle plate, the sections being larger in diameter than a central section of the body section, and a nozzle blade rotatably mounted by at least one of the nozzle holders and the nozzle plate, and located downstream of the nozzle holder with respect to the nozzle flow path, wherein a concave section is recessed by a flow path surface facing the nozzle flow path.where the nozzle holder is formed and at least part of one of the pair of large-diameter sections is incorporated into the concave section. Advantageous effects of the invention

[0007] According to the variable nozzle device of the present disclosure, in a case where the nozzle holder, which has the body section shaped such that the two end sections are thick, is provided, it is possible to suppress the distortion in the flow of exhaust gas colliding with the nozzle blade. Brief description of the drawings Fig. Figure 1 is a diagram schematically showing a configuration of a turbocharger which includes a nozzle device according to some embodiments. Fig. Figure 2 is a longitudinal section view showing an example of a configuration on one side of the turbocharger turbine. Fig. Figure 3 is a diagram that schematically shows a configuration of a nozzle holder according to a first embodiment. Fig. Figure 4 is a diagram that schematically shows a configuration of a nozzle holder and a circumference of the nozzle holder according to the first embodiment. Fig. Figure 5 is a diagram describing a configuration of a countersink hole according to the first embodiment. Fig. Figure 6 is a diagram that schematically shows a configuration of a nozzle holder and a circumference of the nozzle holder according to some embodiments. Fig. Figure 7 is a diagram that schematically shows a configuration of a nozzle holder and a circumference of the nozzle holder according to a second embodiment. Fig. Figure 8 is a diagram describing a configuration of a notch according to the second embodiment. Fig. Figure 9 is a diagram describing a configuration of a notch according to one embodiment. Fig. Figure 10 is a diagram describing a configuration of a notch according to a further embodiment. Description of embodiments

[0008] A variable nozzle device according to one embodiment of the present disclosure is described below with reference to the drawings. Such embodiments illustrate one aspect of the present disclosure, do not limit it, and may be optionally modified within the scope of the technical concept of the present disclosure.

[0009] Fig. Figure 1 is a diagram schematically showing a configuration of a turbocharger 100, which includes a nozzle device 1 according to some embodiments. As in Fig. As shown in Figure 1, the turbocharger 100 includes a turbine 102, a compressor 104, a rotary shaft 106 connecting the turbine 102 and the compressor 104, and a variable nozzle device 1.

[0010] Turbine 102 is driven, for example, by exhaust gas G emitted from machine 200. Compressor 104 compresses intake air A, which is supplied to machine 200, using power from turbine 102, which is transmitted via the rotating shaft 106. Turbine 102 is equipped with variable nozzle 1 for changing the flow velocity or pressure of the exhaust gas G supplied to turbine 102. Turbocharger 100 is a variable-capacity exhaust gas turbocharger. Turbocharger 100 is, for example, mounted on a passenger car.

[0011] Fig. Figure 2 is a longitudinal section view showing an example of a configuration on one side of turbine 102 of turbocharger 100. As in Fig. As shown in Figure 2, the turbine 102 includes a turbine wheel 120, which is provided on one side of the rotating shaft 106, and a turbine housing 122, which accommodates the turbine wheel 120.

[0012] Below, a direction in which an axis line O1 of the rotating shaft 106 extends is defined as an axial direction D1, a direction from the compressor 104 to the turbine 102 is defined as one side of the axial direction D1, and a direction from the turbine 102 to the compressor 104 is defined as the other side of the axial direction D1. Furthermore, a direction perpendicular to the axis line O1 is defined as a radial direction D2, a direction approaching the axis line O1 in the radial direction D2 is defined as an inside in the radial direction D2, and a direction away from the axis line O1 is defined as an outside in the radial direction D2.

[0013] The turbine housing 122 has an inlet 124 for introducing the exhaust gas G and a discharge port 126 for releasing the exhaust gas G, which has passed through the turbine wheel 120, to the outside. A spiral flow path 128 for guiding the exhaust gas G supplied via the inlet 124 to the turbine wheel 120 and a discharge flow path 130 for releasing the exhaust gas G, which has passed through the turbine wheel 120, via the discharge port 126 are formed within the turbine housing 122. The spiral flow path 128 is located on an outer circumferential side of the turbine wheel 120. In other words, the spiral flow path 128 is located on the outside of the turbine wheel 120 in the radial direction D2. The discharge flow path 130 extends along the axial direction D1 and includes the discharge port 126 at one end on one side of the axial direction D1.The discharge flow path 130 is located on the inside of the screw flow path 128 in the radial direction D2. <Variable Düsenvorrichtung> (First embodiment)

[0014] The configuration of a variable nozzle device 1 according to the first embodiment is described. As in Fig. As shown in Figure 2, the variable nozzle device 1 comprises a nozzle holder 2, a nozzle plate 4, a nozzle holder 6, and a nozzle vane 8. In the Fig. In the embodiment shown in Figure 2, the variable nozzle device 1 further includes a paddle lever 10, a drive ring 12 and an actuator 15.

[0015] The nozzle holder 2 has a ring-shaped and a plate-shaped form. In the case of the Fig. In the embodiment shown in Figure 2, the nozzle holder 2 is attached to a bearing housing 134, which receives a bearing 132 that rotatably supports the rotating shaft 106. The nozzle holder 2 is clamped between the bearing housing 134 and the turbine housing 122.

[0016] The nozzle plate 4 defines a nozzle flow path 3 between the nozzle holder 2 and the nozzle plate 4. The nozzle plate 4 has an annular and a plate shape. The nozzle plate 4 is located on one side of the nozzle holder 2 in the axial direction D1. The nozzle flow path 3 communicates with the screw flow path 128 and carries the exhaust gas G from the screw flow path 128 to the turbine wheel 120.

[0017] Nozzle holder 6 will be described later.

[0018] The nozzle blade 8 is located downstream of the nozzle holder 6 with respect to the nozzle flow path 3. In other words, the nozzle blade 8 is located on the inside of the nozzle holder 6 in the radial direction D2 of the nozzle flow path 3. This nozzle blade 8 is rotatably mounted by at least one of the nozzle holder 2 and the nozzle plate 4.

[0019] At the in Fig. In the embodiment shown in Figure 2, the nozzle blade 8 comprises a blade shaft 14 inserted into a hole 18 formed in the nozzle holder 2, and a blade 16 arranged in the nozzle flow path 3. The hole 18 penetrates the nozzle holder 2 along the axial direction D1. The blade shaft 14 is then inserted into the hole 18, so that the nozzle blade 8 is rotatably mounted by the nozzle holder 2. In other words, the nozzle blade 8 is not supported from one side in the axial direction D1 by the nozzle holder 2 and is cantilevered by the nozzle holder 2. The variable nozzle device 1 comprises several nozzle blades 8 arranged at intervals from one another along a circumferential direction of the rotating shaft 106.Although not shown, in some embodiments the nozzle blades 8 are supported at both ends by the nozzle holder 2 and the nozzle plate 4.

[0020] At the in Fig. In the embodiment shown in Figure 2, the blade 16 is provided on one side of the blade shaft 14 in the axial direction D1 and rotates about a rotation axis O2 of the blade shaft 14. As the blade 16 rotates, the cross-sectional area of ​​the nozzle flow path 3 increases or decreases, thus changing the flow velocity or pressure of the exhaust gas G directed to the turbine wheel 120. For this reason, the variable nozzle device 1 is able to control the boost pressure of the turbine 102. In one embodiment, the rotation axis O2 extends along the axial direction D1. In another embodiment, the axis O1 and the rotation axis O2 are parallel to each other.

[0021] The blade lever 10 is a rod-shaped element extending along the radial direction D2. An inner section 10a of the blade lever 10 is attached on the inside, in the radial direction D2, to the opposite side of the blade shaft 14 in the axial direction D1. Furthermore, an outer section 10b of the blade lever 10 is mechanically connected to the drive ring 12 on the outside, in the radial direction D2. Specifically, the outer section 10b of the blade lever 10 is fitted into a locating hole 19 formed in the drive ring 12.

[0022] The drive ring 12 has an annular shape and is configured to rotate along the circumferential direction of the rotating shaft 106 with respect to the nozzle holder 2. In the Fig. In the embodiment shown in Figure 2, the drive ring 12 is connected to the actuator 15 via a rod-shaped drive shaft 21.

[0023] The actuator 15 rotates the drive ring 12 via the drive shaft 21. The actuator 15 contains, for example, an electric motor, an air cylinder, or the like. In the Fig. In the embodiment shown as an example in Figure 2, the drive of the actuator 15 in the variable nozzle device 1 is transmitted to the nozzle blade 8 via the drive shaft 21, the drive ring 12, and the blade lever 10, and the blade 16 is rotated. Furthermore, although not shown, the variable nozzle device 1 also includes a control device that is electrically connected to the actuator 15. For example, the control device is configured to control the drive of the actuator 15 based on the rotational speed of the machine 200.

[0024] The configuration of nozzle holder 6 is described. Fig. Figure 3 is a diagram that schematically shows a configuration of the nozzle holder 6 according to the first embodiment. Fig. Figure 4 is a diagram that schematically shows a configuration of the nozzle holder 6 and a circumference of the nozzle holder 6 according to the first embodiment.

[0025] As in every one of Fig. 3 and Fig. As shown in Figure 4, the nozzle holder 6 has a rod shape. In the first embodiment, the nozzle holder 6 has a column shape. Then, as shown in Figure 4, the nozzle holder 6 connects the nozzle holder to the column. Fig. Figure 4 shows the nozzle holder 6, the nozzle bracket 2, and the nozzle plate 4. In the present disclosure, a direction in which the nozzle holder 6 extends is defined as an extension direction D3, a direction from the nozzle bracket 2 to the nozzle plate 4 is defined as one side of the extension direction D3, and a direction from the nozzle plate 4 to the nozzle bracket 2 is defined as the other side of the extension direction D3. In one embodiment, the nozzle holder 6 extends along the axial direction D1. In another embodiment, the extension direction D3 and the axial direction D1 are parallel to each other.

[0026] As in Fig. 3 and Fig. As shown in Figure 4, the nozzle holder 6 comprises a body section 20, a nozzle holder connection section 26, and a nozzle plate connection section 28. The body section 20, the nozzle holder connection section 26, and the nozzle plate connection section 28, which configure the nozzle holder 6, can each be integrally configured as a single component.

[0027] As in Fig. As shown in Figure 4, body section 20 is located between nozzle holder 2 and nozzle plate 4. Fig. As shown in Figure 3, body section 20 contains a central section 23 and a pair of sections 24a and 24b with a large diameter. In the Fig. In the embodiment shown in Figure 3, the central section 23 is curved in a concave shape towards a central axis O3 of the nozzle holder 6 in such a way that an outer shape changes easily.

[0028] A large-diameter section 24a contains one end of body section 20 on one side in the extension direction D3. The other large-diameter section 24b contains the other end of body section 20 on the opposite side in the extension direction D3. One large-diameter section 24a is located on the opposite side of the other large-diameter section 24b across the central section 23 in the extension direction D3. Each of the pair of large-diameter sections 24a and 24b has a diameter larger than the diameter of the central section 23. In one embodiment, each of the pair of large-diameter sections 24a and 24b has the same diameter. Each of the pair of large-diameter sections 24a and 24b has the same outer diameter φ1 at an arbitrary position in the extension direction D3.

[0029] The present invention is not limited to the invention described in Fig. The embodiment shown in section 3 is limited as long as each of the pair of large-diameter sections 24a and 24b is configured to have a diameter larger than the diameter of the central section 23. Although not shown, in some embodiments at least one of the pair of large-diameter sections 24a and 24b includes a tapered surface where the outer diameter φ1 increases or decreases to one side or the other in the extension direction D3. Although not shown, in some embodiments one large-diameter section 24a and the other large-diameter section 24b have outer diameters φ1 that differ in size.

[0030] In the first embodiment, as in Fig. As shown in Figure 3, the nozzle holder connection section 26 is connected to the other end face 20b of the body section 20 on the other side in the extension direction D3. The nozzle plate connection section 28 is connected to an end face 20a of the body section 20 on one side in the extension direction D3. Then, as shown in Fig. As shown in Figure 4, the nozzle plate connection section 28 is fitted into a plate-side fitting hole 29, which is formed on a plate-side flow path surface 32 of the nozzle plate 4 on the side of the nozzle flow path 3. The plate-side fitting hole 29 penetrates the nozzle plate 4 along the axial direction D1.

[0031] As in Fig. As shown in Figure 4, a concave section 40 is formed in the nozzle holder 2, which is recessed by a support-side flow path surface 30 facing the nozzle flow path 3. A support-side fitting hole 27, into which the nozzle holder connection section 26 is fitted, is formed in a bottom surface 41 of the concave section 40. The support-side fitting hole 27 penetrates the nozzle holder 2 along the axial direction D1.

[0032] As in Fig. As shown in Figure 4, a portion of the other large-diameter section 24b is received in the concave section 40. In one embodiment, the concave section 40 is recessed from the support-side flow path surface 30 such that it is shallower than a length of the other large-diameter section 24 in the extension direction D3. The bottom surface 41 of the concave section 40 is in contact with the other end surface 20b of the body section 20. In some embodiments, all other large-diameter sections 24b are received in the concave section 40. In the present disclosure, a space (hereinafter referred to as a receiving space 45) of the concave section 40, in which a portion of the other large-diameter section 24b is received, is not included in the nozzle flow path 3.

[0033] In the first embodiment, the concave section 40 contains a countersunk borehole 40A (40) that surrounds the entire circumferential direction of the other large-diameter section 24b. Fig. Figure 5 is a diagram describing a configuration of the countersink 40A according to the first embodiment and shows the nozzle holder 2 viewed from a plate thickness direction (axial direction D1). In the present disclosure, the plate thickness direction of the nozzle holder 2 is the same direction as the axial direction D1.

[0034] If the countersink hole 40A is cut in a direction perpendicular to the axial direction D1, the cross-sectional shape of the countersink hole 40A is circular. For this reason, as shown in Fig. As shown in Figure 5, an opening 42 of the counterbore 40A has a circular shape. In the first embodiment, the outer diameter φ1 of the other large-diameter section 24b is smaller than an inner diameter φ2 of the counterbore 40A. Furthermore, the outer diameter φ1 is approximately the same as the inner diameter φ2 and satisfies, for example, φ1 > φ2 × 0.9. The present disclosure does not restrict the cross-sectional shape of the counterbore 40A to a circular shape. In some embodiments, the cross-sectional shape of the counterbore 40A is rectangular or elliptical. In some embodiments, the counterbore 40A and the pair of large-diameter sections 24b have similar cross-sectional shapes.

[0035] The operation and effects of the variable nozzle device 1 according to the embodiment are described. Since the body section 20 of the nozzle holder 6 contains the central section 23 and the pair of large-diameter sections 24a and 24b, it is possible to prevent a decrease in the bending stiffness of the nozzle holder 6. Furthermore, because the nozzle holder 6 contains the central section 23, its heat capacity can be reduced, and its temperature rise rate at high temperatures can be increased.Furthermore, by increasing the temperature rise rate of the nozzle holder 6 at a high temperature, it is possible to reduce a difference in the amount of thermal expansion between the nozzle holder 6 and the blade 16 during transient heating, and it is possible to prevent the malfunction of the variable nozzle device 1 due to a narrowing of a gap between the blade 16 and the nozzle plate 4 or due to contact between the blade 16 and the nozzle plate 4.

[0036] In a case where the nozzle holder 6 contains the body section 20, which has the pair of large-diameter sections 24a and 24b, the body section 20 has a shape in which both end sections are thick, and the pair of large-diameter sections 24a and 24b significantly affect the flow of the exhaust gas G through the nozzle flow path 3. For this reason, the flow of the exhaust gas G colliding with the nozzle blade 16 can be distorted, leading to an increase in the load on the actuator 15 that rotates the nozzle blade 8, or to an increase in the load on a linkage system (for example, the drive ring 12 or the blade lever 10) that transmits the drive of the actuator 15 to the nozzle blade 8.

[0037] To address such concerns, according to the variable nozzle device 1 in one embodiment, since a portion of the other large-diameter section 24b is incorporated in the concave section 40, the influence on the flow of the exhaust gas G through the nozzle flow path 3 is suppressed. Therefore, in a case where the nozzle holder 6, which includes the body section 20, is shaped such that both end sections are as shown in Fig. 3 shown are thick, has, is provided, possible to suppress distortion of the flow of exhaust gas G that collides with the blade 16.

[0038] According to one embodiment, since the concave section 40 contains the counterbore 40A, the entire circumferential portion of the other large-diameter section 24b is contained within the counterbore 40A, and its influence on the flow of the exhaust gas G through the nozzle flow path 3 can be effectively suppressed. Furthermore, according to another embodiment, since the outer diameter φ1 of the other large-diameter section 24b is approximately the same as the inner diameter φ2 of the counterbore 40A, the majority of the receiving space 45 can be filled by the other large-diameter section 24b. Therefore, it is possible to suppress the influence of the receiving space 45 on the flow of the exhaust gas G through the nozzle flow path 3.

[0039] Fig. Figure 6 is a diagram that schematically shows a configuration of the nozzle holder 6 and a circumference of the nozzle holder 6 according to some embodiments. As in Fig. As shown in Figure 6, a second concave section 50, which is recessed from the plate-side flow path surface 32, is formed at the nozzle plate 4. The mounting-side fitting hole 27, into which the nozzle plate connection section 28 is fitted, is formed on a bottom surface 51 of the second concave section 50.

[0040] As in Fig. As shown in Figure 6, part of one section 24a with a large diameter is incorporated into the second concave section 50. In the Fig. In the embodiment shown in Figure 6, the second concave section 50 is recessed from the plate-side flow path surface 32 such that it is shallower than one length of the large-diameter section 24a in the extension direction D3. The bottom surface 51 of the second concave section 50 is in contact with one end surface 20a of the body section 20. In some embodiments, the entire large-diameter section 24a is contained within the second concave section 50. In the present disclosure, the space of the second concave section 50 is not included in the nozzle flow path 3.

[0041] According to the in Fig. In the configuration shown in Figure 6, since part of the pair of large-diameter sections 24a is incorporated into the second concave section 50, the influence on the flow of the exhaust gas G through the nozzle flow path 3 is further suppressed. Therefore, in a case where the nozzle holder 6, which has the body section 20 shaped such that both end sections are thick, is provided, it is possible to further suppress distortion of the flow of the exhaust gas G colliding with the blade 16. (Second embodiment)

[0042] A variable nozzle device 1 according to a second embodiment of the present disclosure is described. The variable nozzle device 1 according to the second embodiment differs from the first embodiment in that the concave section 40 includes a notch 40B. In the second embodiment, the same components as in the first embodiment are designated by the same reference numerals, and the detailed descriptions thereof are not repeated.

[0043] The configuration of the nozzle holder 6 according to the second embodiment is described. Fig. Figure 7 is a diagram schematically showing a configuration of the nozzle holder 6 and a circumference of the nozzle holder 6 according to the second embodiment. In the second embodiment, as shown in Fig. 7 shown, the concave section 40 has a notch 40B (40) which is recessed from the support-side flow path surface 30 such that an outer circumferential edge 60 of the nozzle support 2 is included. Fig. Figure 8 is a diagram describing a configuration of notch 40B according to the second embodiment and shows the nozzle holder 2 when viewed from the plate thickness direction.

[0044] As in Fig. As shown in Figure 8, the notch 40B comprises a first side surface 62, which faces the receiving space 45 from one side in the circumferential direction (hereinafter referred to as a circumferential direction D4) of the nozzle holder 2, and a second side surface 64, which faces the receiving space 45 from the other side in the circumferential direction D4. In the second embodiment, the center of the nozzle holder 2 is located on the axis line O1 of the rotating shaft 106. One side of the circumferential direction D4 is an upstream side in the direction of rotation of the rotating shaft 106, and the other side of the circumferential direction D4 is a downstream side in the direction of rotation of the rotating shaft 106.

[0045] In the second embodiment, the notch 40B includes a connecting surface 66 that joins the first side surface 62 and the second side surface 64. The first side surface 62 and the second side surface 64 each extend in a linear shape. The connecting surface 66 is curved in a concave shape towards the inside in the radial direction D2. The receiving space 45 is surrounded by the bottom surface 41, the first side surface 62, the second side surface 64, and the connecting surface 66. In some embodiments, at least one of the first side surface 62 and the second side surface 64 extends along a logarithmic spiral shape.

[0046] As in Fig. As shown in Figure 8, a first straight line L1 is defined, passing through each of the axis lines O1 of the rotating shaft 106 and the central axis O3 of the nozzle holder 6. A second straight line L2 is defined, passing through each of the central axis O3 of the nozzle holder 6 and a midpoint O4 between an end 63 on the outside of the first side surface 62 in the radial direction D2 and an end 65 on the outside of the second side surface 64 in the radial direction D2. An angle θ of an included angle formed by the first straight line L1 and the second straight line L2 is 45 degrees or greater. In the second embodiment, the angle θ is equal to or greater than 60 degrees and equal to or less than 75 degrees.

[0047] The operation and effects of the variable nozzle device 1 according to the second embodiment are described. According to the second embodiment, the concave section 40 in the nozzle holder 2 can be easily formed by applying the notch 40B, compared to a case where the countersink 40A is used.

[0048] In one case, where the variable nozzle device 1 is mounted on the turbocharger 100 (variable-capacity exhaust gas turbocharger), the exhaust gas G, which is swirling in the screw flow path 128, flows into the nozzle flow path 3. According to the second embodiment, since the angle θ is 45 degrees or more, the notch 40B extends along the radial direction D2 such that it follows the flow of the exhaust gas G through the nozzle flow path 3. Therefore, it is possible to suppress the influence of the notch 40B on the flow of the exhaust gas G through the nozzle flow path 3. In particular, the exhaust gas G, which is swirling through the screw flow path 128, flows into the nozzle flow path 3 in a region where a flow angle θ2, defined by a tangent line L3 at the inlet of the nozzle flow path 3 and a direction of the flow of the exhaust gas G, is 15 degrees or more and 30 degrees or less (see Fig. 8) For this reason, since the angle θ satisfies 60 degrees or more and 75 degrees or less, the notch 40B extends along the flow of the exhaust gas G, which flows into the nozzle flow path 3 at the flow angle θ2. Therefore, it is possible to effectively suppress the influence of the notch 40B on the flow of the exhaust gas G through the nozzle flow path 3.

[0049] The configuration of notch 40B is not based on the one in Fig. 8. The embodiment shown is limited. Fig. Figure 9 is a diagram describing a configuration of notch 40B according to one embodiment. Fig. Figure 10 is a diagram describing a configuration of notch 40B according to a further embodiment.

[0050] In one embodiment, as in Fig. As shown in Figure 9, a distance X between the first side surface 62 and the second side surface 64 is constant. In another embodiment, the first side surface 62 and the second side surface 64 are separated from each other towards the outside in the radial direction D2. That is, the distance X increases towards the outside in the radial direction D2. In a case where the concave section 40 is the counterbore 40A, a vortex is formed by a gap between an inner circumferential surface of the counterbore 40A and an outer circumferential surface of the other large-diameter section 24b, and there are concerns that the vortex may affect the flow (main flow) of the exhaust gas G flowing through the nozzle flow path 3. To address such concerns, according to the [reference to Figure 9], the following is done: Fig. 9 and Fig. In the exemplary configuration shown in Figure 10, the concave section 40 corresponds to the notch 40B, thus inhibiting vortex formation. Furthermore, according to the Fig. In the configuration shown in Figure 10, it is possible to suppress the influence of a stagnation point formed on the outside (upstream side) of the nozzle holder 6 in the radial direction D2 of the nozzle flow path 3 and to reduce a change in the flow of the exhaust gas G around the nozzle holder 6.

[0051] Although not shown, in some embodiments the second concave section 50 includes a second notch which is recessed from the plate-side flow path surface 32 in such a way that an outer circumferential edge of the nozzle plate 4 is included.

[0052] For example, the content described in each of the embodiments described above is understood as follows.

[0053] [1] A variable nozzle device (1) according to the present disclosure comprises a nozzle holder (2), a nozzle plate (4) defining a nozzle flow path (3) between the nozzle holder and the nozzle plate, a rod-shaped nozzle holder (6) connecting the nozzle holder and the nozzle plate, the nozzle holder (6) comprising a pair of large-diameter sections (24a) and (24b) provided at both ends in an extension direction (D3) in a body section (20) located between the nozzle holder and the nozzle plate, the sections being larger in diameter than a central section (23) of the body section, and a nozzle blade (8) rotatably mounted by at least one of the nozzle holder and the nozzle plate, the blade being located downstream of the nozzle holder with respect to the nozzle flow path, the blade having a concave section (40) extending from a flow path surface (30),which is recessed towards the nozzle flow path, is formed at the nozzle support and at least part of one (24b) of the pair of large diameter sections is received in the concave section.

[0054] In a case where the nozzle holder contains the body section having a pair of large-diameter sections (the body section has a shape where both end sections are thick), the pair of large-diameter sections significantly influences the flow of the fluid (exhaust gas) through the nozzle flow path. According to the configuration described above in [1], at least part of one of the pair of large-diameter sections is contained within the concave section, thus suppressing the influence on the flow of the fluid through the nozzle flow path. Therefore, in a case where the nozzle holder is provided with the body section shaped such that both end sections are thick, it is possible to suppress the distortion of the exhaust gas flow colliding with the nozzle blade.

[0055] [2] In some embodiments, in the configuration described above in [1], the concave section includes a countersunk hole (40A) that surrounds an entire circumferential direction of the large-diameter section.

[0056] According to the configuration described above in [2], since at least part of the large diameter section is completely enclosed in the concave section in the circumferential direction, it is possible to effectively suppress the influence on the flow of the fluid passing through the nozzle flow path.

[0057] [3] In some embodiments, in the configuration described above in [1], the nozzle holder has an annular shape, and the concave section includes a notch (40B) which is recessed from the flow path surface of the nozzle holder such that an outer circumferential edge (60) of the nozzle holder is included.

[0058] According to the configuration described above in [3], in comparison to [2] above, the concave section can be easily formed at the nozzle holder.

[0059] [4] In some embodiments, in the configuration described above in [3], the notch includes a first side surface (62) facing a receiving space (45) in which at least a part of the large-diameter section is received from one side in a circumferential direction of the nozzle holder, and a second side surface (64) facing the receiving space from the other side in the circumferential direction, and the first side surface and the second side surface are each separated from each other towards an outside in a radial direction of the nozzle holder.

[0060] According to the configuration described above in [4], it is possible to suppress the influence of a stagnation point formed on an upstream side of the nozzle holder with respect to the nozzle flow path and to reduce a change in the flow of the fluid around the nozzle holder.

[0061] [5] In some embodiments, in the configuration described above in [4], the nozzle holder is attached to a bearing housing (134) which receives a bearing (132) which rotatably supports a rotating shaft (106), the notch extends to an upstream side in a direction of rotation of the rotating shaft towards the outside in the radial direction, and in a case where the nozzle holder is viewed from a plate thickness direction, an angle θ formed by a first straight line (L1) passing through each axis line (O1) of the rotating shaft and a center of the nozzle holder, and a second straight line (L2) passing through each center of the nozzle holder and a center between an end of the first side surface on the outside in the radial direction and an end of the second side surface on the outside in the radial direction, is 45 degrees or more.

[0062] In a case where the variable nozzle device is mounted on a turbocharger, a fluid swirling in the screw flow path flows into the nozzle flow path. According to the configuration described above in [5], since the concave section extends along the flow of the fluid passing through the nozzle flow path, it is possible to suppress the influence of the concave section on the flow of the fluid passing through the nozzle flow path.

[0063] [6] In some embodiments, the angle is 60 degrees or more and 75 degrees or less in the configuration described above in [5].

[0064] In a case where the variable nozzle device is mounted on the turbocharger, the fluid swirling in the screw flow path flows into a nozzle flow path in a region where the flow angle is 15 degrees or more and 30 degrees or less. According to the configuration described above in [6], since the concave section extends along the flow of the fluid passing through the nozzle flow path, it is possible to suppress the influence of the concave section on the flow of the fluid passing through the nozzle flow path.

[0065] [7] In some embodiments, in the configuration described above in [1] to [6], a second concave section (50) is formed in the nozzle plate, which is recessed by a second flow path surface (32) facing the nozzle flow path, and at least part of the other (24a) of the pair of large diameter sections is included in the second concave section.

[0066] According to the configuration described above in [7], at least part of the other of the pair of large-diameter sections is incorporated into the second concave section, thus further suppressing the influence on the flow of the fluid passing through the nozzle flow path. Therefore, in a case where the nozzle holder is provided with the body section shaped such that both end sections are thick, it is possible to further suppress the distortion of the exhaust gas flow colliding with the nozzle blade.

[0067] [8] An exhaust gas turbocharger (100) of the variable capacity type according to the present disclosure comprises a turbine (102) driven by exhaust gas (G) discharged from a machine (200), a compressor (104) which compresses air supplied to the machine by driving the turbine, and the variable nozzle device (1) which is described in [1] to [7] above and which changes a flow velocity of the exhaust gas supplied to the turbine.

[0068] According to the configuration described above in [8], it is possible to provide the variable capacity exhaust gas turbocharger in which the variable nozzle device described in one of [1] to [7] above is fitted. Reference symbol list 1 variable nozzle device 2 nozzle holders 3 Nozzle flow path 4 nozzle plates 6 nozzle holders 8 nozzle blades 10 shovel levers 12 Drive ring 14 Blade shaft 15 Actuator 16 shovel blade 20 Body section 23 Middle section 24a a section with a large diameter 24b the other large-diameter section 26 Nozzle holder connection section 27 Mounting-side pass hole 28 Nozzle plate connection section 29 plate-side pass hole 30 mounting-side flow path area 32 plate-side flow path area 40 concave section 40A Countersunk hole 40B notch 45 Recording room 50 second concave section 60 outer perimeter edge 62 first side surface 64 second side surface 100 turbochargers 102 Turbine 104 Compressor 106 Rotary shaft 120 turbine wheel 122 turbine housings 124 Introductory admission 126 Delivery connection 128 Snail flow path 130 discharge flow path 132 warehouses 134 Bearing housings 200 machine A Intake air D1 Axial direction D2 Radial direction D3 Extension direction D4 Circumferential direction Exhaust gas L1 first straight line L2 second straight line O1 axis line O2 axis of rotation O3 Center line X distance θ angle θ2 flow angle 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] JP 6655755

[0003]

Claims

[1] Variable nozzle device, comprising: a nozzle holder; a nozzle plate that defines a nozzle flow path between the nozzle holder and the nozzle plate; a rod-shaped nozzle holder connecting the nozzle holder and the nozzle plate, comprising a pair of large-diameter sections provided at both ends in one direction of extension within a body section located between the nozzle holder and the nozzle plate, and which are larger in diameter than a central section of the body section; and a nozzle blade which is rotatably mounted by at least one of the nozzle holder and the nozzle plate and which is located downstream of the nozzle holder with respect to the nozzle flow path, wherein a concave section, which is recessed from a flow path surface facing the nozzle flow path, is formed at the nozzle holder, and at least part of one of the pair of large-diameter sections is included in the concave section. [2] Variable nozzle device according to claim 1, wherein the concave section includes a countersink hole that surrounds an entire circumferential direction of the large diameter section. [3] Variable nozzle device according to claim 1, wherein the nozzle holder has an annular shape and the concave section includes a notch which is recessed from the flow path surface of the nozzle holder such that an outer circumferential edge of the nozzle holder is included. [4] Variable nozzle device according to claim 3, wherein the notch comprises a first side surface facing a receiving space in which at least a part of the large diameter section is received from one side in a circumferential direction of the nozzle holder, and a second side surface facing the receiving space from the other side in the circumferential direction, and the first side surface and the second side surface are each separated from each other towards an outside in a radial direction of the nozzle holder. [5] Variable nozzle device according to claim 4, wherein the nozzle holder is attached to a bearing housing which accommodates a bearing which rotatably supports a rotating shaft, the notch extends towards an upstream side in a direction of rotation of the rotating shaft towards the outside in the radial direction, and In a case where the nozzle holder is viewed from a plate thickness direction, an angle formed by a first straight line passing through each axis of the rotating shaft and a center of the nozzle holder, and a second straight line passing through each center of the nozzle holder and a midpoint between an end of the first side surface on the outside in the radial direction and an end of the second side surface on the outside in the radial direction, shall be 45 degrees or more. [6] Variable nozzle device according to claim 5, wherein the angle is 60 degrees or more and 75 degrees or less. [7] Variable nozzle device according to any one of claims 1 to 6, wherein a second concave section, which is recessed by a second flow path surface facing the nozzle flow path, is formed in the nozzle plate, and at least part of the other of the pair of large-diameter sections is incorporated into the second concave section. [8] Variable-capacity exhaust gas turbocharger comprising: a turbine that is driven by exhaust gas emitted from a machine; a compressor that compresses air supplied to the machine by driving the turbine; and the variable nozzle device according to one of claims 1 to 6, which changes the flow velocity of the exhaust gas supplied to the turbine.

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