A method for designing a variable nozzle device, and a variable nozzle device.

Abstract

Provided is a method for designing a variable nozzle device including a nozzle mount and a nozzle vane that is rotatably supported by the nozzle mount, the nozzle vane having a vane shaft that is inserted into a hole formed in the nozzle mount, and a vane blade that is disposed in a nozzle flow path through which a fluid flows. The method comprises: a setting step for setting a fluid force that the fluid exerts on the vane blade, a rotational moment that is generated by the fluid force around a rotational axis of the nozzle vane, the length of the hole, the diameter of the vane shaft, the height of the vane blade, and a friction coefficient of the vane shaft against the hole; and a determination step for determining shapes of the nozzle mount and the nozzle vane to satisfy formula 1 where Fv is the fluid force set in the setting step, Tv is the rotational moment, tm is the length of the hole, dm is the diameter of the vane shaft, hv is the height of the vane blade, and μ is the friction coefficient.

Description

Technical Field

[0001] The present disclosure relates to a design method of a variable nozzle device and a variable nozzle device.

Background Art

[0002] Conventionally, a variable displacement exhaust turbocharger that supercharges the intake air of an engine by utilizing the energy of the exhaust gas of the engine is known (see, for example, Patent Document 1). The variable displacement exhaust turbocharger adjusts the cross-sectional area of a nozzle flow path that sends exhaust gas from a scroll flow path of a turbine housing to a turbine wheel by a variable nozzle device, thereby changing the flow velocity and pressure of the exhaust gas sent to the turbine wheel to enhance the supercharging effect.

[0003] [[ID=1,5]] The variable nozzle device can adjust the flow path cross-sectional area of the nozzle flow path by changing the opening degree of nozzle vanes arranged in the nozzle flow path from the outside by an actuator.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The nozzle vanes are designed to have a rotational moment on the side that opens the valve by the fluid force acting on the nozzle vanes. If this rotational moment is larger than the frictional torque generated between a support member (nozzle mount) that rotatably supports the nozzle vanes and the nozzle vanes, no play occurs in the link system that is linked to transmit the drive of the actuator to the nozzle vanes (for example, the contact position between the vane lever and the drive ring does not change) whether the nozzle vanes are opening or closing.

[0006] However, when the rotational moment becomes smaller than the friction torque, play occurs in the linkage system in order to allow the nozzle vane to open. As a result, even if the actuator drive is the same, the degree of nozzle vane opening may vary depending on the play in the linkage system, potentially reducing the controllability of the nozzle vane opening.

[0007] This disclosure has been made in view of the above-mentioned problems, and aims to provide a method for designing a variable nozzle device that can improve the controllability of the nozzle vane opening, and a variable nozzle device. [Means for solving the problem]

[0008] To achieve the above objective, a method for designing a variable nozzle device according to the present disclosure includes a nozzle mount and a nozzle vane rotatably supported on the nozzle mount, the nozzle vane having a vane shaft inserted into a hole formed in the nozzle mount and vane blades arranged in a nozzle channel through which fluid flows, the method comprising: a setting step of setting the fluid force acting on the vane blades by the fluid, the rotational moment due to the fluid force generated around the rotation axis of the nozzle vane, the length of the hole, the diameter of the vane shaft, the height of the vane blades, and the coefficient of friction of the vane shaft with respect to the hole; and a determination step of determining the shapes of the nozzle mount and the nozzle vane, respectively, such that the following equation (1) is satisfied, where Fv is the fluid force set in the setting step, Tv is the rotational moment, tm is the length of the hole, dm is the diameter of the vane shaft, hv is the height of the vane blades, and μ is the coefficient of friction. Tv>μ×dm / 2×Fv(1+hv / tm)···(1)

[0009] To achieve the above objective, the design method for a variable nozzle device according to the present disclosure includes a nozzle mount, a nozzle plate defining a nozzle flow path through which fluid flows between the nozzle mount and the nozzle mount, and a nozzle vane rotatably supported on the nozzle mount and the nozzle plate, the nozzle vane having a first vane shaft inserted into a first hole formed in the nozzle mount, a second vane shaft inserted into a second hole formed in the nozzle plate, and vane blades arranged in the nozzle flow path, wherein the fluid force acting on the vane blades and the rotation axis of the nozzle vane are generated The method comprises a setting step of setting the rotational moment due to the fluid force generated, the diameter of the first vane shaft, the diameter of the second vane shaft, the first friction coefficient of the first vane shaft with respect to the first hole, and the second friction coefficient of the second vane shaft with respect to the second hole, and a determination step of determining the shapes of the nozzle mount, the nozzle plate, and the nozzle vane, respectively, such that the following equation (5) is satisfied, given that the fluid force set in the setting step is Fv, the rotational moment is Tv, the diameter of the first vane shaft is dm1, the diameter of the second vane shaft is dm2, the first friction coefficient is μ1, and the second friction coefficient is μ2. Tv>Fv×(μ1dm1+μ2dm2) / 4···(5)

[0010] To achieve the above objective, the variable nozzle device according to the present disclosure comprises a nozzle mount, and a nozzle vane rotatably supported by the nozzle mount, the nozzle vane including a vane shaft inserted into a hole formed in the nozzle mount, and vane blades arranged in a nozzle channel through which fluid flows, wherein Fv is the fluid force acting on the vane blades by the fluid, Tv is the rotational moment due to the fluid force generated around the rotation axis of the nozzle vane, tm is the length of the hole, dm is the diameter of the vane shaft, hv is the height of the vane blades, and μ is the coefficient of friction of the vane shaft with respect to the hole, The condition Tv > μ × dm / 2 × Fv(1 + hv / tm) is satisfied.

[0011] To achieve the above objective, the variable nozzle device according to the present disclosure comprises a nozzle mount, a nozzle plate defining a nozzle passage through which fluid flows between the nozzle mount and the nozzle plate, and a nozzle vane rotatably supported on the nozzle mount and the nozzle plate, the nozzle vane including a first vane shaft inserted into a first hole formed in the nozzle mount, a second vane shaft inserted into a second hole formed in the nozzle plate, and vane blades arranged in the nozzle passage, wherein Fv is the fluid force acting on the vane blades by the fluid, Tv is the rotational moment due to the fluid force generated around the rotation axis of the nozzle vane, dm1 is the diameter of the first vane shaft, dm2 is the diameter of the second vane shaft, μ1 is the first coefficient of friction of the first vane shaft with respect to the first hole, and μ2 is the second coefficient of friction of the second vane shaft with respect to the second hole. Tv > Fv × (μ1dm1 + μ2dm2) / 4 [Effects of the Invention]

[0012] According to the design method and variable nozzle device of this disclosure, the controllability of the nozzle vane opening can be improved. [Brief explanation of the drawing]

[0013] [Figure 1] This diagram schematically shows the configuration of a turbocharger equipped with a variable nozzle device according to several embodiments. [Figure 2] This is a longitudinal cross-sectional view showing an example of the configuration on the turbine side of a supercharger. [Figure 3] This diagram schematically shows the state of a variable nozzle device according to one embodiment when exhaust gas is flowing through the nozzle passage. [Figure 4] This diagram schematically shows the state of a variable nozzle device according to another embodiment when exhaust gas is flowing through the nozzle passage. [Figure 5] This is a flowchart showing a design method for a variable nozzle device according to one embodiment. [Figure 6] This graph shows the relationship between the coefficient of friction and the nozzle vane opening. [Figure 7] It is a graph showing the relationship between the opening degree of the nozzle vane obtained by CFD analysis and Tv / Fv. [Figure 8] It is a flowchart showing a design method of a variable nozzle device according to another embodiment.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, a variable nozzle device and a design method of a variable nozzle device according to an embodiment of the present disclosure will be described based on the drawings. Such an embodiment shows one aspect of the present disclosure, does not limit this disclosure, and can be arbitrarily changed within the scope of the technical idea of this disclosure.

[0015] FIG. 1 is a diagram schematically showing a configuration of a supercharger 100 including a variable nozzle device 1 according to some embodiments. As shown in FIG. 1, the supercharger 100 includes a turbine 102, a compressor 104, a rotating shaft 106 connecting the turbine 102 and the compressor 104, and a variable nozzle device 1.

[0016] The turbine 102 is rotationally driven, for example, by exhaust gas G discharged from an engine 200. The compressor 104 compresses intake air A supplied to the engine 200, with the power of the turbine 1 being transmitted via the rotating shaft 106. The turbine 102 is provided with a variable nozzle device 1 for changing the flow velocity and pressure of the exhaust gas G supplied to the turbine 102. Such a supercharger 100 is a so-called variable displacement type exhaust turbocharger and is mounted on, for example, a passenger car

[0017] FIG. 2 is a longitudinal sectional view showing an example of a configuration on the turbine 102 side of the supercharger 100. As shown in FIG. 2, the turbine 102 includes a turbine rotor 120 provided on one side of the rotating shaft 106 and a turbine housing 122 housing the turbine rotor 120.

[0018] Hereinafter, the direction in which the axis O1 of the rotating shaft 106 extends is defined as the axial direction D1. The direction from the compressor 104 toward the turbine 102 is defined as one side of the axial direction D1, and the direction from the turbine 102 toward the compressor 104 is defined as the other side of the axial direction D1. Further, the direction perpendicular to the axis O1 is defined as the radial direction D2. Among the radial directions D2, the direction approaching the axis O1 is defined as the inner side of the radial direction D2, and the direction away from the axis O1 is defined as the outer side of the radial direction D2.

[0019] The turbine housing 122 has an inlet 124 for introducing the exhaust gas G therein and an outlet 126 for discharging the exhaust gas G that has passed through the turbine rotor 120 to the outside. Inside the turbine housing 122, a scroll flow path 128 for guiding the exhaust gas G introduced through the inlet 124 to the turbine rotor 120 and a discharge flow path 130 for discharging the exhaust gas G that has passed through the turbine rotor 120 through the outlet 126 are formed. The scroll flow path 128 is located on the outer peripheral side of the turbine rotor 120. In other words, the scroll flow path 128 is located on the outer side of the radial direction D2 with respect to the turbine rotor 120. The discharge flow path 130 extends along the axial direction D1 and includes the outlet 126 at one end on one side of the axial direction D1.

[0020] <Variable nozzle device> The configuration of the variable nozzle device 1 according to an embodiment will be described. As shown in FIG. 2, the variable nozzle device 1 includes a nozzle mount 2 and a nozzle vane 4. In the form illustrated in FIG. 2, the variable nozzle device 1 further includes a nozzle plate 6, a vane lever 8, a drive ring 10, and an actuator 20.

[0021] The nozzle mount 2 has an annular and plate shape. In the form illustrated in FIG. 2, the nozzle mount 2 is fixed to a bearing housing 134 that houses a bearing 132 for rotatably supporting the rotating shaft 106. This nozzle mount 2 is sandwiched between the bearing housing 134 and the turbine housing 122.

[0022] The nozzle vane 4 is rotatably supported by the nozzle mount 2. This nozzle vane 4 includes a vane shaft 14 inserted into a hole 18 formed in the nozzle mount 2, and vane blades 16 arranged in the nozzle passage 12 through which the exhaust gas G flows (described later). In the embodiment illustrated in Figure 2, the hole 18 penetrates the nozzle mount 2 along the axial direction D1. The nozzle vane 4 is rotatably supported by the nozzle mount 2 by the insertion of the vane shaft 14 into this hole 18. In other words, the nozzle vane 4 is supported by the nozzle mount 2 from the other side of the axial direction D1. This nozzle vane 4 is not supported from one side of the axial direction D1, but is cantilevered by the nozzle mount 2. The variable nozzle device 1 is provided with a plurality of nozzle vanes 4 arranged at intervals from each other along the circumferential direction of the rotating shaft 106.

[0023] The vane blade 16 is located on one side of the vane shaft 14 in the axial direction D1 and rotates around the rotation axis O2 of the vane shaft 14. As the vane blade 16 rotates, the cross-sectional area of ​​the nozzle passage 12 increases or decreases, causing changes in the flow velocity and pressure of the exhaust gas G guided to the turbine rotor 120. For this reason, the variable nozzle device 1 can control the supercharge pressure of the turbine 102. In one embodiment, the rotation axis O2 extends along the axial direction D1. In one embodiment, the axis O1 and the rotation axis O2 are parallel to each other.

[0024] The nozzle plate 6 has an annular and plate shape. The nozzle plate 6 is located on one side in the axial direction D1 from the nozzle mount 2 and defines a nozzle flow path 12 between it and the nozzle mount 2. The nozzle flow path 12 communicates with the scroll flow path 128 and guides the exhaust gas G from the scroll flow path 128 to the turbine rotor 120. Although not shown, the variable nozzle device 1 may further include nozzle supports that support the nozzle mount 2 and the nozzle plate 6, respectively, in a spaced-out manner.

[0025] The vane lever 8 is a rod-shaped member extending along the radial direction D2. The inner portion 8a of the vane lever 8, on the inner side in the radial direction D2, is fixed to the other side in the axial direction D1 of the vane shaft 14. Furthermore, the outer portion 8b of the vane lever 8, on the outer side in the radial direction D2, is mechanically connected to the drive ring 10. Specifically, the outer portion 8b of the vane lever 8 is fitted into a fitting hole 11 formed in the drive ring 10.

[0026] The drive ring 10 has an annular shape and is configured to rotate along the circumferential direction of the rotating shaft 106 relative to the nozzle mount 2. In the embodiment illustrated in Figure 2, the drive ring 10 is connected to the actuator 20 via a rod-shaped drive shaft 22.

[0027] The actuator 20 rotates the drive ring 10 via the drive shaft 22. The actuator 20 includes, for example, an electric motor or an air cylinder. In the embodiment illustrated in Figure 2, the variable nozzle device 1 is configured such that the drive of the actuator 20 is transmitted to the nozzle vane 4 via the drive shaft 22, the drive ring 10, and the vane lever 8, causing the vane blade 16 to rotate. The variable nozzle device 1 also further includes a control device 24 electrically connected to the actuator 20. The control device 24 is configured to control the drive of the actuator 20, for example, based on the rotational speed of the engine 200.

[0028] Figure 3 is a schematic diagram showing the state of a variable nozzle device 1 according to one embodiment when exhaust gas G is flowing through the nozzle passage 12. As shown in Figure 3, let Fv be the fluid force acting on the vane blade 16 by the exhaust gas G, Tv be the rotational moment due to the fluid force Fv generated around the rotation axis O2, tm be the length of the hole 18, dm be the diameter of the vane shaft 14, hv be the height of the vane blade 16, and μ be the coefficient of friction of the vane shaft 14 with respect to the hole 18. In one embodiment of the variable nozzle device 1, Tv > μ × dm / 2 × Fv(1 + hv / tm) is satisfied.

[0029] Here, the direction in which the fluid force Fv acts is perpendicular to the axis of rotation O2. The fluid force Fv is, for example, the magnitude of the force exerted by the exhaust gas G on the vane blade 16 when the engine 200 is idling or operating at its maximum rotational speed. The fluid force Fv is the magnitude of the force exerted by the exhaust gas G on the vane blade 16 immediately after the engine 200 is started.

[0030] In some embodiments, the fluid force Fv is a force generated in accordance with the pressure distribution that occurs around the vane blade 16 when the exhaust gas G flows through the nozzle passage 12 from the scroll passage 128 toward the turbine rotor 120. In some embodiments, the fluid force Fv is calculated by adding the pressure distribution of the nozzle passage 12 to the pressure distribution that occurs around the vane blade 16 when the exhaust gas G flows through the nozzle passage 12 from the scroll passage 128 toward the turbine rotor 120.

[0031] (Effects / Actions) As illustrated in Figure 2, the variable nozzle device 1 includes a linkage system (vane lever 8, drive ring 10, etc.) that links (connects) each other to transmit the drive of the actuator 20 to the nozzle vane 4. When the rotational moment Tv becomes smaller than the friction torque Tf generated between the nozzle mount 2 and the nozzle vane 4, play occurs in the linkage system to allow it to function. For example, when opening the nozzle vane 4, the contact position between the outer part 8b of the vane lever 8 and the inner surface of the fitting hole 11 of the drive ring 10 changes. Therefore, even if the drive of the actuator 20 is the same, the opening degree of the nozzle vane 4 may shift according to the play in the linkage system, potentially reducing the controllability of the opening degree of the nozzle vane 4.

[0032] To address such concerns, the operation and effects of a variable nozzle device 1 according to one embodiment will be explained with reference to Figure 3. As shown in Figure 3, when a fluid force Fv acts on the vane blade 16, the vane shaft 14 inserted into the hole 18 tilts. The vane shaft 14 includes a first position P1 and a second position P2 that contact the inner circumferential surface 19 of the hole 18. In Figure 3, the second position P2 is located radially D2 inward (towards the turbine rotor 120) than the first position P1. If the contact load acting on the first position P1 is F1 and the contact load acting on the second position P2 is F2, then F2 = F1 + Fv holds. Also, as the balance of moments around the first position P1, F2 × tm - Fv × (tm + hv / 2) holds. From these two equations, F1 = Fv × hv / 2tm and F2 = Fv(1 + hv / 2tm) are obtained.

[0033] Furthermore, the friction torque Tf is given by Tf = μ × dm / 2 × (F1 + F2), and it is considered that Tf = μ × dm / 2 × Fv(1 + hv / tm) holds true. According to one embodiment, Tv > μ × dm / 2 × Fv(1 + hv / tm) is satisfied. In other words, rotational moment Tv > friction torque Tf is satisfied. Therefore, whether the nozzle vane 4 is open or closed, there is no play in the linkage system for operating the nozzle vane 4 (for example, the contact position between the vane lever 8 and the drive ring 10 does not change). As a result, the controllability of the opening degree of the nozzle vane 4 can be improved.

[0034] In one embodiment of the variable nozzle device 1, the nozzle vane 4 was cantilevered by the nozzle mount 2, but in another embodiment, the nozzle vane 4 is cantilevered by both the nozzle mount 2 and the nozzle plate 6.

[0035] Figure 4 is a schematic diagram showing the state of a variable nozzle device 1 according to another embodiment when exhaust gas G is flowing through the nozzle passage 12. As illustrated in Figure 4, in another embodiment, the nozzle vane 4 further includes a second vane shaft 26 provided at the tip of the vane blade 16 opposite to the vane shaft 14 (first vane shaft) side in the direction in which the rotation axis O2 extends. The second vane shaft 26 is fitted into a second hole 28 formed in the nozzle plate 6. In the embodiment illustrated in Figure 4, each of the holes 18 and the second hole 28 is of the same diameter. Each of the holes 18 and the second hole 28 is formed at the same position in the radial direction D2. Each of the vane shafts 14 and the second vane shaft 26 is of the same diameter.

[0036] As shown in Figure 4, Fv is the fluid force acting on the vane blade 16 by the exhaust gas G, Tv is the rotational moment due to the fluid force generated around the rotation axis O2 of the nozzle vane 4, dm1 is the diameter of the vane shaft 14, dm2 is the diameter of the second vane shaft 26, μ1 is the first friction coefficient of the vane shaft 14 (first vane shaft) with respect to the hole 18 (first hole), and μ2 is the second friction coefficient of the second vane shaft 26 with respect to the second hole 28. In another embodiment of the variable nozzle device 1, Tv > Fv × (μ1dm1 + μ2dm2) / 4.

[0037] As shown in Figure 4, when a fluid force Fv acts on the vane blade 16, the vane shaft 14 comes into contact with the inner surface 19 of the hole 18, and the second vane shaft 26 comes into contact with the inner surface 29 of the second hole 28. If F1 is the contact load acting on the inner surface 19 of the hole 18, and F2 is the contact load acting on the inner surface 29 of the second hole 28, then Fv = F1 + F2 holds. If we consider F1 and F2 to be equal to each other, then we obtain F1 = Fv / 2 and F2 = Fv / 2, respectively.

[0038] When the nozzle vane 4 is supported by both the nozzle mount 2 and the nozzle plate 6 (i.e., the nozzle vane 4 is double-supported), if the friction torque generated in the nozzle vane 4 is Tf, then Tf = μ1 × dm1 / 2 × F1 + μ2 × dm2 / 2 × F2, and it is considered that Tf = Fv × (μ1dm1 + μ2dm2) / 4 holds true. Furthermore, according to another embodiment, Tv > Fv × (μ1dm1 + μ2dm2) / 4 is satisfied. In other words, rotational moment Tv > friction torque Tf is satisfied. For this reason, when the nozzle vane 4 is double-supported, the controllability of the opening degree of the nozzle vane 4 can be improved.

[0039] <Design method for variable nozzle devices> A design method for a variable nozzle device 1 according to one embodiment will be described. Specifically, a design method for a variable nozzle device 1 when the nozzle vane 4 is cantilevered and supported by the nozzle mount 2 will be described. Figure 5 is a flowchart of the design method for a variable nozzle device 1 according to one embodiment. As shown in Figure 5, the design method for the variable nozzle device 1 includes a setting step S1 and a determination step S2.

[0040] In setting step S1, the following are set: the fluid force acting on the vane blade 16 by the exhaust gas G, the rotational moment due to the fluid force generated around the rotation axis O2 of the nozzle vane 4, the length of the hole 18, the diameter of the vane shaft 14, the height of the vane blade 16, and the coefficient of friction of the vane shaft 14 with respect to the hole 18.

[0041] In the determination step S2, assuming that the fluid force set in the setting step S1 is Fv, the rotational moment is Tv, the length of the hole 18 is tm, the diameter of the vane shaft 14 is dm, the height of the vane blade 16 is hv, and the coefficient of friction is μ, the shapes of the nozzle mount 2 and nozzle vane 4 are determined to satisfy equation (1). Tv>μ×dm / 2×Fv(1+hv / tm)···(1)

[0042] According to the design method for the variable nozzle device 1 according to one embodiment, the shapes of the nozzle mount 2 and the nozzle vane 4 are determined such that Tv > μ × dm / 2 × Fv(1 + hv / tm). In other words, the shapes of the nozzle mount 2 and the nozzle vane 4 are determined such that rotational moment Tv > friction torque Tf. Therefore, whether the nozzle vane 4 is open or closed, there is no play in the linkage system for operating the nozzle vane 4 (for example, the contact position between the vane lever 8 and the drive ring 10 does not change). As a result, the controllability of the opening degree of the nozzle vane 4 can be improved.

[0043] In some embodiments, the determination step S2 determines the shapes of the nozzle mount 2 and the nozzle vane 4 respectively so as to satisfy equation (2). Tv / {dm / 2×Fv(1+hv / tm)}>0.4···(2)

[0044] Transforming equation (1), we obtain μ>Tv / {dm / 2×Fv(1+hv / tm)}. The right-hand side of this equation, Tv / {dm / 2×Fv(1+hv / tm)}, is defined as the open friction coefficient μ0, which is the threshold for opening the nozzle vane 4. Figure 6 is a graph showing the relationship between the open friction coefficient μ0 and the opening degree of the nozzle vane 4, where the horizontal axis represents the opening degree of the nozzle vane 4 and the vertical axis represents the open friction coefficient μ0. As shown in Figure 6, the open friction coefficient μ0 tends to increase as the opening degree of the nozzle vane 4 increases. In Figure 6, L1 and L2 are the opening degrees of the nozzle vane 4, which has a vane blade 16 (curved blade) designed for the purpose of rectifying the turbine blade inlet flow. The vane blades 16 in L1 and L2 are of different sizes.

[0045] As shown in Figure 6, the opening friction coefficient μ0 changes according to the opening degree of the nozzle vane 4. For example, in L1, when the opening degree of the nozzle vane 4 is the first opening degree X1, the opening friction coefficient μ0 is approximately 0.3. In other words, unless the friction coefficient μ is approximately 0.3 or less, the nozzle vane 4 cannot be opened by the fluid force Fv, and there is a risk of play occurring in the link system. Here, the opening degree of the nozzle vane 4 that has a large impact on the controllability of the nozzle vane 4 is defined as the second opening degree X2. In one embodiment, the second opening degree X2 is included in the region of small opening degrees (closer to fully closed than fully open in Figure 6). Then, as shown in Figure 6, when the opening friction coefficient μ0 is 0.4 or more, in L1, when the opening degree of the nozzle vane 4 is 2 or more than the second opening degree X2, the nozzle vane 4 is opened by the fluid force Fv, and no play occurs in the link system. Similarly, when the friction coefficient μ0 is 0.4 or greater, in L2, the fluid force Fv opens the nozzle vane 4 in the range excluding the third opening X3 where the opening of the nozzle vane 4 is slightly larger than the second opening X2, thus preventing play in the link system. Thus, through our diligent research, we have found that by setting the friction coefficient μ to 0.4, it is possible to maintain a state in which no play occurs in the link system in the main part of the nozzle vane 4 opening, even if the size of the vane blade 16 is changed. Therefore, by satisfying equation (2), the controllability of the nozzle vane 4 opening can be improved in the main part of the nozzle vane 4 opening.

[0046] In some embodiments, the determination step S2 determines the respective shapes of the nozzle mount 2 and the nozzle vane 4 so as to satisfy equation (3). dm / 2 × (1 + hv / tm) < 4 ... (3)

[0047] Transforming equation (2), we get dm / 2 × (1 + hv / tm) < 2.5 × Tv / Fv. CFD analysis is performed on Tv / Fv on the right side of this equation by changing the shape of the nozzle vane 4. Figure 7 is a graph showing the relationship between the nozzle vane 4 opening and Tv / Fv obtained by CFD analysis, where the horizontal axis represents the nozzle vane 4 opening and the vertical axis represents Tv / Fv. As shown in Figure 7, there is a tendency for Tv / Fv to increase as the nozzle vane 4 opening increases. In Figure 7, L3 to L6 are the openings of nozzle vanes 4 with vane blades 16 (curved blades) designed for the purpose of straightening the turbine blade inlet flow. The size and shape of the vane blades 16 differ from each other in L3 to L6.

[0048] As described above, the nozzle vane 4 is significantly affected by changes in its opening angle in the region where the opening angle of the nozzle vane 4 is small. Through diligent research by the inventors, it was found that, as shown in Figure 7, in the region where the opening angle of the nozzle vane 4 is less than or equal to the third opening angle X3, Tv / Fv is approximately 1.5 to 2.0 mm. In other words, if dm / 2 × (1 + hv / tm) < 4 is satisfied, it is possible to maintain a state in which there is no play in the link system even when the opening angle of the nozzle vane 4 is less than or equal to the third opening angle X3. For this reason, by determining the shapes of the nozzle mount 2 and the nozzle vane 4 so as to satisfy equation (3), the controllability of the opening angle of the nozzle vane 4 when the opening angle of the nozzle vane 4 is less than or equal to the third opening angle X3 can be improved.

[0049] In some embodiments, the determination step S2 determines the respective shapes of the nozzle mount 2 and the nozzle vane 4 so as to satisfy equation (4). 1 + hv / tm < 2 ... (4)

[0050] When designing the variable nozzle device 1, the diameter dm of the vane shaft 14 is often set to approximately 4 to 5 mm. Therefore, by determining the shapes of the nozzle mount 2 and the nozzle vane 4 so as to satisfy equation (4), the controllability of the opening degree of the nozzle vane 4 when the diameter dm of the vane shaft 14 is set to 4 to 5 mm can be improved.

[0051] As shown in Figure 5, the design method of the variable nozzle device 1 according to one embodiment further includes a shift step S3. The shift step S3, after the determination step S2, shifts the rotation axis O2 of the nozzle vane 4 to a position 2 mm or more upstream of the nozzle flow path 12, or 10% or more of the length of the cord of the vane 16, relative to the position where the exhaust gas G acts on the vane blade 16. In other words, the vane axis 14 is shifted 2 mm or more upstream of the nozzle flow path 12, or 10% or more of the length of the cord of the vane 16.

[0052] The upper limit of the amount by which the rotation axis O2 of the nozzle vane 4 is shifted is not particularly limited, but is set based on, for example, the output value of the actuator 20 or the amount of wear of the link system (upper limit of contact load).

[0053] In the modified equation (2), dm / 2 × (1 + hv / tm) < 2.5 × Tv / Fv, increasing the value on the right-hand side expands the applicable dimensional range of the nozzle mount 2 and nozzle vane 4. The vane blade 16 is pressed by the differential pressure between the space outside the vane blade 16 radially D2 (on the scroll flow path 128 side) and the space inside the vane blade 16 radially D2 (on the turbine rotor 120 side), so it is considered that there is a point of application of the fluid force Fv near the center of the vane blade 16.

[0054] Furthermore, when the point of application is located in the center of the vane blade 16, the rotational moment Tv can be increased by shifting the rotation axis O2 of the nozzle vane 4 to the upstream side of the nozzle flow path 12, making it easier to achieve rotational moment Tv > friction torque Tf. Through diligent research by the inventors, it has been found that by setting the shift amount to 2 mm or more, it is possible to more favorably maintain a state in which no play occurs in the link system. In addition, when this variable nozzle device 1 is installed in a turbocharger for a passenger car, the cord length of the vane blade 16 is often designed to be approximately 20 mm. For this reason, by setting the shift amount to 10% or more of the cord length of the vane blade 16, it is possible to more favorably maintain a state in which no play occurs in the link system. Therefore, by executing the shift step S3, it is possible to more favorably maintain a state in which no play occurs in the link system.

[0055] A design method for a variable nozzle device 1 according to another embodiment will be described. Specifically, a design method for a variable nozzle device 1 in which the nozzle vane 4 is supported by both the nozzle mount 2 and the nozzle plate 6 will be described. Figure 8 is a flowchart of the design method for a variable nozzle device 1 according to another embodiment. As shown in Figure 8, the design method for the variable nozzle device 1 includes a setting step S11 and a determination step S12.

[0056] Setting step S11 sets the fluid force acting on the vane blade 16 by the exhaust gas G, the rotational moment due to the fluid force generated around the rotation axis O2 of the nozzle vane 4, the diameter of the vane shaft 14, the diameter of the second vane shaft 26, the first friction coefficient of the vane shaft 14 with respect to the hole 18, and the second friction coefficient of the second vane shaft 26 with respect to the second hole 28.

[0057] In the determination step S12, the shapes of the nozzle mount 2, nozzle plate 6, and nozzle vane 4 are determined such that equation (5) is satisfied, where Fv is the fluid force set in the setting step S11, Tv is the rotational moment, dm1 is the diameter of the vane shaft 14, dm2 is the diameter of the second vane shaft 26, μ1 is the first friction coefficient, and μ2 is the second friction coefficient. Tv>Fv×(μ1dm1+μ2dm2) / 4···(5)

[0058] According to a design method for a variable nozzle device 1 according to another embodiment, the shapes of the nozzle mount 2, nozzle plate 6, and nozzle vane 4 are determined such that Tv > Fv × (μ1dm1 + μ2dm2) / 4. In other words, the shapes of the nozzle mount 2, nozzle plate 6, and nozzle vane 4 are determined such that rotational moment Tv > friction torque Tf. Therefore, whether the nozzle vane 4 is open or closed, there is no play in the linkage system for operating the nozzle vane 4 (for example, the contact position between the vane lever and the drive ring does not change). As a result, the controllability of the opening degree of the nozzle vane 4 can be improved.

[0059] In some embodiments, the determination step S12 determines the shapes of the nozzle mount 2, nozzle plate 6, and nozzle vane 4 respectively so as to satisfy equation (6). Tv > μ1 × Fv × dm1 / 2 ... (6)

[0060] When equation (6) is satisfied, the controllability of the nozzle vane 4 opening can be improved when μ1 = μ2 and dm1 = dm2.

[0061] In some embodiments, the determination step S12 determines the shapes of the nozzle mount 2, nozzle plate 6, and nozzle vane 4 respectively so as to satisfy equation (7). Tv / {Fv×(dm1+dm2)}>0.1···(7)

[0062] As described above, by setting the friction coefficient μ to 0.4, it is possible to maintain a state in which there is no play in the link system at the main part of the nozzle vane 4 opening. Substituting 0.4 for μ1 and μ2 in equation (5), we obtain Tv / {Fv×(dm1+dm2)}>0.1. Therefore, by satisfying equation (7), the controllability of the nozzle vane 4 opening at the main part of the nozzle vane 4 opening can be improved.

[0063] In some embodiments, the determination step S12 determines the shapes of the nozzle mount 2, nozzle plate 6, and nozzle vane 4 respectively so as to satisfy equation (8). Tv / (Fv×dm1)>0.2···(8)

[0064] As described above, by setting the friction coefficient μ to 0.4, it is possible to maintain a state in which there is no play in the link system at the main part of the nozzle vane 4 opening. Substituting 0.4 for μ1 in equation (6), we obtain Tv / (Fv×dm1)>0.2. Therefore, by satisfying equation (8), the controllability of the nozzle vane 4 opening at the main part of the nozzle vane 4 opening can be improved.

[0065] As shown in Figure 8, the design method for the variable nozzle device 1 according to another embodiment further includes a shift step S13. The shift step S13, after the determination step S12, shifts the rotation axis O2 of the nozzle vane 4 to a position upstream of the nozzle flow path 12 by 2 mm or more, or by 10% or more of the length of the cord of the vane blade 16, from the position where the exhaust gas G acts on the vane blade 16. In other words, the vane axis 14 and the second vane axis 26 are each shifted upstream of the nozzle flow path 12 by 2 mm or more, or by 10% or more of the length of the cord of the vane blade 16.

[0066] The contents described in each of the above embodiments can be understood, for example, as follows:

[0067] [1] The design method for the variable nozzle device (1) relating to this disclosure is: A method for designing a variable nozzle device, comprising: a nozzle mount (2); a nozzle vane (4) rotatably supported by the nozzle mount, the nozzle vane having a vane shaft (14) inserted into a hole (18) formed in the nozzle mount, and a vane blade (16) positioned in a nozzle channel (12) through which a fluid (G) flows; Setting step (S1) sets the fluid force acting on the vane blade by the fluid, the rotational moment due to the fluid force generated around the rotation axis (O2) of the nozzle vane, the length of the hole, the diameter of the vane shaft, the height of the vane blade, and the coefficient of friction of the vane shaft with respect to the hole. The device comprises a determination step (S2) in which, assuming that the fluid force set in the setting step is Fv, the rotational moment is Tv, the length of the hole is tm, the diameter of the vane axis is dm, the height of the vane blade is hv, and the coefficient of friction is μ, the shape of the nozzle mount and the nozzle vane are determined to satisfy the following equation (1). Tv>μ×dm / 2×Fv(1+hv / tm)···(1)

[0068] If Tf is the friction torque generated between the nozzle mount and the nozzle vane, then it is considered that Tf = μ × dm / 2 × Fv(1 + hv / tm) holds true. According to the method described in [1] above, the shapes of the nozzle mount and nozzle vane are determined such that Tv > μ × dm / 2 × Fv(1 + hv / tm). In other words, the shapes of the nozzle mount and nozzle vane are determined such that rotational moment Tv > friction torque Tf. Therefore, whether the nozzle vane is open or closed, there is no play in the linkage system for operating the nozzle vane (for example, the contact position between the vane lever and the drive ring does not change). As a result, the controllability of the nozzle vane opening can be improved.

[0069] [2] In some embodiments, the method described in [1] above, The aforementioned decision step determines the shapes of the nozzle mount and the nozzle vane, respectively, so as to satisfy the following equation (2). Tv / {dm / 2×Fv(1+hv / tm)}>0.4···(2)

[0070] Through diligent research by the present inventors, it has been found that by setting the friction coefficient μ to 0.4, it is possible to maintain a state in which no play occurs in the link system (a state in which the nozzle vanes open due to fluid force). Therefore, the method described in [2] above can improve the controllability of the nozzle vane opening.

[0071] [3] In some embodiments, the method described in [2] above, The aforementioned decision step determines the shapes of the nozzle mount and the nozzle vane, respectively, so as to satisfy the following equation (3). dm / 2 × (1 + hv / tm) < 4 ... (3)

[0072] Transforming equation (2), we get dm / 2 × (1 + hv / tm) < 2.5 × Tv / Fv. In the region of small nozzle vane openings, the influence of opening degree changes on controllability is significant. Through diligent research by the inventors, it was found that in the region of small nozzle vane openings, Tv / Fv is approximately 1.5 to 2.0. In other words, if dm / 2 × (1 + hv / tm) < 4 is satisfied, it is possible to maintain a state in which no play occurs in the link system even when the nozzle vane opening is small. For this reason, the method described in [3] above can improve the controllability of the nozzle vane opening in the region of small openings.

[0073] [4] In some embodiments, the method described in [3] above, The aforementioned decision step determines the shapes of the nozzle mount and the nozzle vane, respectively, so as to satisfy the following equation (4). 1 + hv / tm < 2 ... (4)

[0074] When designing a variable nozzle device, the vane axis diameter dm is often set to approximately 4 to 5. The method described in [4] above can improve the controllability of the nozzle vane opening when the vane axis diameter dm is set to 4 to 5.

[0075] [5] In some embodiments, the method described in any one of [2] to [4] above, The method further includes a shift step (S3) after the determination step, in which the rotation axis of the nozzle vane is shifted by 2 mm or more upstream of the nozzle flow path from the position where the fluid acts on the vane blade, or by 10% or more of the length of the cord of the vane blade.

[0076] When the point of application of the fluid force Fv acting on the vane blade is located at the center of the vane blade, the rotational moment Tv can be increased by shifting the rotation axis of the nozzle vane upstream of the nozzle flow path, making it easier to achieve rotational moment Tv > friction torque Tf. Through diligent research by the inventors, it has been found that by setting the shift amount to 2 mm or more, it is possible to more favorably maintain a state in which no play occurs in the link system. Furthermore, when this variable nozzle device is installed in a turbocharger for a passenger car, the cord length of the vane blade is often designed to be approximately 20 mm. For this reason, by setting the shift amount to 10% or more of the length of the vane blade cord, it is possible to more favorably maintain a state in which no play occurs in the link system. According to the method described in [5] above, it is possible to more favorably maintain a state in which no play occurs in the link system.

[0077] [6] The design method for the variable nozzle device (1) relating to this disclosure is: A method for designing a variable nozzle device, comprising: a nozzle mount (2); a nozzle plate (6) defining a nozzle passage (12) through which a fluid (G) flows between the nozzle mount and the nozzle plate; and a nozzle vane (4) rotatably supported on the nozzle mount and the nozzle plate, the nozzle vane having a first vane shaft (14) inserted into a first hole (18) formed in the nozzle mount, a second vane shaft (26) inserted into a second hole (28) formed in the nozzle plate, and a vane blade (16) positioned in the nozzle passage; Setting step (S11) for setting the fluid force acting on the vane blade by the fluid, the rotational moment due to the fluid force generated around the rotation axis of the nozzle vane, the diameter of the first vane shaft, the diameter of the second vane shaft, the first friction coefficient of the first vane shaft with respect to the first hole, and the second friction coefficient of the second vane shaft with respect to the second hole, The system includes a determination step (S12) in which, assuming that the fluid force set in the setting step is Fv, the rotational moment is Tv, the diameter of the first vane shaft is dm1, the diameter of the second vane shaft is dm2, the first friction coefficient is μ1, and the second friction coefficient is μ2, the shape of the nozzle mount, the nozzle plate, and the nozzle vane are determined to satisfy the following equation (5). Tv>Fv×(μ1dm1+μ2dm2) / 4···(5)

[0078] When the nozzle vane is supported by the nozzle mount and the nozzle plate, respectively, if the friction torque generated in the nozzle vane is Tf, then the following equation is considered to hold: Tf = Fv × (μ1dm1 + μ2dm2) / 4. According to the method described in [6] above, the shapes of the nozzle mount, nozzle plate, and nozzle vane are determined such that Tv > Fv × (μ1dm1 + μ2dm2) / 4. In other words, the shapes of the nozzle mount, nozzle plate, and nozzle vane are determined such that rotational moment Tv > friction torque Tf. Therefore, whether the nozzle vane is open or closed, there is no play in the linkage system for operating the nozzle vane (for example, the contact position between the vane lever and the drive ring does not change). This improves the controllability of the nozzle vane opening.

[0079] [7] In some embodiments, the method described in [6] above, The aforementioned decision step determines the shapes of the nozzle mount, the nozzle plate, and the nozzle vane, respectively, so as to satisfy the following equation (6). Tv > μ1 × Fv × dm1 / 2 ... (6)

[0080] According to the method described in [7] above, the controllability of the nozzle vane opening can be improved when μ1 = μ2 and dm1 = dm2.

[0081] [8] In some embodiments, in the method described in [6] above, The aforementioned decision step determines the shapes of the nozzle mount, the nozzle plate, and the nozzle vane, respectively, so as to satisfy the following equation (7). Tv / {Fv×(dm1+dm2)}>0.1···(7)

[0082] As described above, by setting the friction coefficient μ to 0.4, it is possible to maintain a state in which no play occurs in the link system. Substituting 0.4 for μ1 and μ2 in equation (5), we obtain Tv / {Fv×(dm1+dm2)}>0.1. Therefore, the method described in [8] above can improve the controllability of the nozzle vane opening.

[0083] [9] In some embodiments, the method described in [7] above, The aforementioned decision step determines the shapes of the nozzle mount, the nozzle plate, and the nozzle vane, respectively, so as to satisfy the following equation (8). Tv / (Fv×dm1)>0.2···(8)

[0084] As described above, by setting the friction coefficient μ to 0.4, it is possible to maintain a state in which no play occurs in the link system. Substituting 0.4 for μ1 in equation (6), we obtain Tv / (Fv×dm1)>0.2. Therefore, the method described in [9] above can improve the controllability of the nozzle vane opening.

[0085]

[10] The variable nozzle device (1) relating to this disclosure is Nozzle mount (2), A nozzle vane (4) rotatably supported on the nozzle mount, comprising a vane shaft (14) inserted into a hole (18) formed in the nozzle mount, and a vane blade (16) arranged in a nozzle passage (12) through which a fluid (G) flows, If Fv is the fluid force acting on the vane blade by the fluid, Tv is the rotational moment generated around the rotation axis (O2) of the nozzle vane due to the fluid force, tm is the length of the hole, dm is the diameter of the vane axis, hv is the height of the vane blade, and μ is the coefficient of friction of the vane axis with respect to the hole, The condition Tv > μ × dm / 2 × Fv(1 + hv / tm) is satisfied.

[0086] If Tf is the friction torque generated between the nozzle mount and the nozzle vane, then the equation Tf = μ × dm / 2 × Fv(1 + hv / tm) is considered to hold. According to the configuration described in

[10] above, Tv > μ × dm / 2 × Fv(1 + hv / tm) is satisfied. In other words, rotational moment Tv > friction torque Tf is satisfied. Therefore, whether the nozzle vane is open or closed, there is no play in the linkage system for operating the nozzle vane (for example, the contact position between the vane lever and the drive ring does not change). As a result, the controllability of the nozzle vane opening can be improved.

[0087]

[11] The variable nozzle device (1) relating to this disclosure is Nozzle mount (2), A nozzle plate (6) defines a nozzle passage (12) through which fluid (G) flows between it and the nozzle mount, A nozzle vane (4) rotatably supported by the nozzle mount and the nozzle plate, each comprising a first vane shaft (14) inserted into a first hole (18) formed in the nozzle mount, a second vane shaft (26) inserted into a second hole (28) formed in the nozzle plate, and a vane blade (16) arranged in the nozzle flow path, If Fv is the fluid force acting on the vane blade by the fluid, Tv is the rotational moment generated around the rotation axis (O2) of the nozzle vane due to the fluid force, dm1 is the diameter of the first vane shaft, dm2 is the diameter of the second vane shaft, μ1 is the first friction coefficient of the first vane shaft with respect to the first hole, and μ2 is the second friction coefficient of the second vane shaft with respect to the second hole, Tv > Fv × (μ1dm1 + μ2dm2) / 4

[0088] When the nozzle vane is supported by the nozzle mount and the nozzle plate, respectively, if Tf is the friction torque generated in the nozzle vane, then the following equation is considered to hold: Tf = Fv × (μ1dm1 + μ2dm2) / 4. According to the configuration described in

[11] above, Tv > Fv × (μ1dm1 + μ2dm2) / 4 is satisfied. In other words, rotational moment Tv > friction torque Tf is satisfied. Therefore, whether the nozzle vane is open or closed, there is no play in the linkage system for operating the nozzle vane (for example, the contact position between the vane lever and the drive ring does not change). This improves the controllability of the nozzle vane opening. [Explanation of Symbols]

[0089] 1. Variable nozzle device 2 Nozzle Mounts 4 Nozzle vanes 6 Nozzle Plate 8. Vane Lever 10 drive rings 12 Nozzle flow path 14 vane shaft 16. Bane Wing 18 holes 19 Inner circumferential surface of the hole 20 Actuators 22 Drive shaft 24 Control device 26. Second vane axis 28 2nd hole 29 Inner circumferential surface of the second hole 100 Supercharger 102 Turbine 104 Compressor 106 Rotating Shaft 120 Turbine Rotor 122 Turbine Housing 124 Inlet 126 Outlet 128 Scroll channel 130 Discharge channel 132 Bearings 134 Bearing Housing 200 engine A Intake D1 Axial direction D2 radial direction G exhaust gas O1 axis O2 rotation axis P1 1st position P2 2nd position S1, S11 Setup Steps S2, S12 Decision Step S3, S13 Shift Step

Claims

1. A method for designing a variable nozzle device, comprising: a nozzle mount; a nozzle vane rotatably supported by the nozzle mount, the nozzle vane having a vane shaft inserted into a hole formed in the nozzle mount; and a vane blade positioned in a nozzle channel through which fluid flows; A setting step in which the fluid force acting on the vane blade by the fluid, the rotational moment due to the fluid force generated around the rotation axis of the nozzle vane, the length of the hole, the diameter of the vane shaft, the height of the vane blade, and the coefficient of friction of the vane shaft with respect to the hole are set, The system includes a determination step in which, assuming that the fluid force set in the setting step is Fv, the rotational moment is Tv, the length of the hole is tm, the diameter of the vane axis is dm, the height of the vane blade is hv, and the coefficient of friction is μ, the shape of the nozzle mount and the nozzle vane are determined to satisfy the following equation (1). Design method for variable nozzle devices. Tv>μ×dm / 2×Fv(1+hv / tm)...(1)

2. The aforementioned determination step determines the shapes of the nozzle mount and the nozzle vane, respectively, so as to satisfy the following equation (2): A method for designing a variable nozzle device according to claim 1. Tv / {dm / 2×Fv(1+hv / tm)}>0.4...(2)

3. The aforementioned decision step determines the shapes of the nozzle mount and the nozzle vane, respectively, so as to satisfy the following equation (3): A method for designing a variable nozzle device according to claim 2. dm / 2×(1+hv / tm)<4...(3)

4. The aforementioned decision step determines the shapes of the nozzle mount and the nozzle vane, respectively, so as to satisfy the following equation (4): A method for designing a variable nozzle device according to claim 3. 1+hv / tm<2...(4)

5. The method further includes a shift step, after the determination step, in which the rotation axis of the nozzle vane is shifted by 2 mm or more upstream of the nozzle flow path from the position where the fluid acts on the vane blade, or by 10% or more of the length of the chord of the vane blade. A method for designing a variable nozzle device according to any one of claims 2 to 4.

6. A method for designing a variable nozzle device, comprising: a nozzle mount; a nozzle plate defining a nozzle flow path through which fluid flows between the nozzle mount and the nozzle plate; and nozzle vanes rotatably supported by the nozzle mount and the nozzle plate, respectively, the vanes having a first vane shaft inserted into a first hole formed in the nozzle mount, a second vane shaft inserted into a second hole formed in the nozzle plate, and vane blades arranged in the nozzle flow path, wherein A setting step of setting the fluid force acting on the vane blade by the fluid, the rotational moment due to the fluid force generated around the rotation axis of the nozzle vane, the diameter of the first vane shaft, the diameter of the second vane shaft, the first friction coefficient of the first vane shaft with respect to the first hole, and the second friction coefficient of the second vane shaft with respect to the second hole, The system includes a determination step in which, assuming that the fluid force set in the setting step is Fv, the rotational moment is Tv, the diameter of the first vane shaft is dm1, the diameter of the second vane shaft is dm2, the first friction coefficient is μ1, and the second friction coefficient is μ2, the shape of the nozzle mount, the nozzle plate, and the nozzle vane are determined to satisfy the following equation (5). Design method for variable nozzle devices. Tv>Fv×(μ1dm1+μ2dm2) / 4...(5)

7. The aforementioned determination step determines the shapes of the nozzle mount, the nozzle plate, and the nozzle vane, respectively, so as to satisfy the following formula (6). A method for designing a variable nozzle device according to claim 6. Tv>μ1×Fv×dm1 / 2...(6)

8. The aforementioned decision step determines the shapes of the nozzle mount, the nozzle plate, and the nozzle vane, respectively, so as to satisfy the following formula (7): A method for designing a variable nozzle device according to claim 6. Tv / {Fv×(dm1+dm2)}>0.1...(7)

9. The aforementioned decision step determines the shapes of the nozzle mount, the nozzle plate, and the nozzle vane, respectively, such that they satisfy the following formula (8). A method for designing a variable nozzle device according to claim 7. Tv / (Fv×dm1)>0.2...(8)

10. Nozzle mount and, A nozzle vane rotatably supported on the nozzle mount, comprising a vane shaft inserted into a hole formed in the nozzle mount, and a vane blade arranged in a nozzle passage through which fluid flows, If Fv is the fluid force acting on the vane blade by the fluid, Tv is the rotational moment generated around the rotation axis of the nozzle vane due to the fluid force, tm is the length of the hole, dm is the diameter of the vane axis, hv is the height of the vane blade, and μ is the coefficient of friction of the vane axis with respect to the hole, The following conditions satisfy Tv > μ × dm / 2 × Fv(1 + hv / tm): Variable nozzle device.

11. Nozzle mount and, A nozzle plate that defines a nozzle channel through which fluid flows between it and the nozzle mount, A nozzle vane rotatably supported by the nozzle mount and the nozzle plate, comprising a first vane shaft inserted into a first hole formed in the nozzle mount, a second vane shaft inserted into a second hole formed in the nozzle plate, and a nozzle vane including vane blades arranged in the nozzle flow path, If Fv is the fluid force acting on the vane blade by the fluid, Tv is the rotational moment generated around the rotation axis of the nozzle vane due to the fluid force, dm1 is the diameter of the first vane axis, dm2 is the diameter of the second vane axis, μ1 is the first friction coefficient of the first vane axis with respect to the first hole, and μ2 is the second friction coefficient of the second vane axis with respect to the second hole, The following conditions must be met: Tv > Fv × (μ1dm1 + μ2dm2) / 4 Variable nozzle device.

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