JP7100993B2 - Centrifugal compressor and turbocharger - Google Patents

Description

The present invention relates to centrifugal compressors and turbochargers.

Conventionally, a technique related to a turbocharger equipped with a centrifugal compressor is known. For example, in Patent Document 1, a guide blade (means for generating a swirling flow) that is rotatably arranged inside a housing and imparts a swirling flow to the intake gas with respect to an impeller wheel that compresses the intake gas flowing from the intake port. A centrifugal compressor and a turbocharger equipped with the above are disclosed. In this device, a swirling flow is applied to the intake gas by the guide blades to regulate the flow toward the impeller wheel, suppress the stall of the centrifugal compressor, and expand the range in which the device can be operated stably. There is.

Japanese Patent No. 5649758

By the way, in the centrifugal compressor and the turbocharger as described in Patent Document 1, it is desirable to aim at further expansion of the operation range by making the flow rate of the fluid supplied to the centrifugal compressor variable. However, in a mass-produced and small-sized device such as a turbocharger, a specific method for obtaining a centrifugal compressor having a variable supply flow rate without complicating the device has not been established. Therefore, it is required to realize a variable displacement centrifugal compressor with a simple structure.

The present invention has been made in view of the above, and an object of the present invention is to provide a centrifugal compressor having a simple structure and a variable supply flow rate, and a turbocharger equipped with the centrifugal compressor.

In order to solve the above-mentioned problems and achieve the object, the centrifugal compressor according to the present invention includes a casing in which an intake passage is formed, an impeller that rotationally compresses a fluid supplied from the intake passage, and the impeller. A flow rate adjusting device for adjusting the flow rate of the fluid supplied to the fluid is provided, and the flow rate adjusting device is rotatable about a direction orthogonal to the rotation axis of the impeller in the intake passage. It has a plurality of inlet guide blades attached to the casing and imparting a turning force to the fluid supplied to the impeller, and the plurality of inlet guide blades are directed from the inner wall of the casing toward the rotation shaft side. When the wing apex is located on the outer diameter side of the innermost diameter portion of the inlet of the impeller, and the wing surfaces of the plurality of inlet guide blades are located at the first position orthogonal to the mainstream direction of the fluid. The blade surfaces of the inlet guide blades arranged adjacent to each other are arranged in a row along the circumferential direction of the rotation axis.

With this configuration, a plurality of inlet guide blades that apply a turning force to the fluid supplied to the impeller are positioned at the first position, and the blade surfaces are lined up in a row along the circumferential direction of the rotation axis to accommodate the intake passage. The outer diameter side can be trimmed to narrow the passage width of the intake passage. As a result, the supply flow rate can be adjusted by using the inlet guide blade for imparting the swivel blade to the fluid supplied to the impeller. That is, one flow rate adjusting device can have both a function for applying a turning force and a function for adjusting the flow rate. Therefore, according to the centrifugal compressor according to the present invention, it is possible to provide a centrifugal compressor having a variable supply flow rate with a simple structure.

Further, it is preferable that the protrusion length of the casing from the inner wall of the plurality of inlet guide blades is 5% or more and 45% or less of the inlet radius of the impeller.

With this configuration, when multiple inlet guide blades are positioned in the first position, the inlet of the impeller is not excessively blocked, the fluid is stably supplied to the impeller, and the centrifugal compressor is stable. Can be driven. Further, when the plurality of inlet guide blades rotate from the first position, an appropriate turning force can be applied to the fluid.

Further, the flow rate adjusting device includes a drive unit for rotating the plurality of inlet guide blades and a control unit for controlling the drive unit, and the control unit has a flow rate of the fluid of a predetermined flow rate or less. When the drive unit positions the plurality of inlet guide blades at the first position and the flow rate of the fluid is larger than the predetermined flow rate, the drive unit increases the flow rate and causes the plurality of inlets. It is preferable to increase the rotation angle of the guide blade from the first position.

With this configuration, when the flow rate supplied to the impeller is small, which is less than or equal to the predetermined flow rate, the flow rate of the mainstream supplied to the impeller is further reduced by the plurality of inlet guide blades positioned at the first position, and the flow rate is centrifugal. The operating range of the compressor can be expanded on the small flow rate side. On the other hand, when the flow rate is larger than the predetermined flow rate, the mainstream can be smoothly guided to the impeller by applying a turning force to the mainstream by the plurality of inlet guide blades. As a result, the stall of the centrifugal compressor can be suppressed, and the stable operation of the centrifugal compressor can be achieved.

Further, when the flow rate is a second predetermined flow rate larger than the predetermined flow rate, the control unit makes the plurality of inlet guide blades horizontal to the mainstream direction by the drive unit. Positioned at the second position, when the flow rate of the fluid is larger than the second predetermined flow rate, the drive unit rotates the plurality of inlet guide blades from the second position in response to the increase in the flow rate. It is preferable to increase the angle.

With this configuration, when the flow rate supplied to the impeller is larger than the predetermined flow rate and the flow rate is larger than the second predetermined flow rate, the second position where the blade surface is horizontal with respect to the mainstream direction of the plurality of inlet guide blades. The mainstream can be smoothly guided to the impeller by further rotating from. As a result, the stall of the centrifugal compressor can be suppressed even at a large flow rate, and the centrifugal compressor can be operated stably.

Further, it is preferable that the plurality of inlet guide blades are provided so as to be movable in the axial direction of the rotation shaft, and move away from the impeller as they rotate from the first position.

With this configuration, when the plurality of inlet guide blades are positioned at the first position and the outer diameter side of the intake passage is trimmed, the plurality of inlet guide blades can be positioned at positions relatively close to the impeller. As a result, it is possible to prevent the mainstream cut by the plurality of inlet guide blades from flowing back near the inner wall of the intake passage before reaching the impeller. Also, when the plurality of inlet guide blades are located between the first position and the second position, the plurality of inlet guide blades should not be too close to the impeller and should turn appropriately in the mainstream direction. Power can be applied.

In order to solve the above-mentioned problems and achieve the object, the turbocharger according to the present invention is characterized by including the above-mentioned centrifugal compressor.

With this configuration, it becomes possible to provide a turbocharger equipped with a centrifugal compressor having a variable supply flow rate due to a simple structure.

FIG. 1 is an explanatory diagram showing an outline of a centrifugal compressor and a turbocharger according to an embodiment. FIG. 2 is an explanatory diagram showing an outline of a centrifugal compressor according to an embodiment. FIG. 3 is a perspective view showing a vicinity in which a plurality of inlet guide blades are arranged in the centrifugal compressor according to the embodiment. FIG. 4 is a perspective view showing an entrance guide wing. FIG. 5 is a schematic view showing an intake passage in a state where a plurality of inlet guide blades are positioned at the first position. FIG. 6 is a schematic view showing an intake passage in a state where a plurality of inlet guide blades are positioned at the second position. FIG. 7 is an explanatory diagram showing an example of the operation range of the centrifugal compressor of the present embodiment. FIG. 8 is a schematic explanatory view for explaining the action of applying a swirling force to the mainstream of the fluid toward the impeller. FIG. 9 is a schematic explanatory view for explaining the action of applying a swirling force to the mainstream of the fluid toward the impeller. FIG. 10 is a schematic explanatory view for explaining the action of applying a swirling force to the mainstream of the fluid toward the impeller. FIG. 11 is an explanatory diagram schematically showing the operation of the inlet guide blade in the modified example of the centrifugal compressor according to the embodiment. FIG. 12 is an explanatory diagram schematically showing the operation of the inlet guide blade in the modified example of the centrifugal compressor according to the embodiment.

Hereinafter, embodiments of the centrifugal compressor and turbocharger according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment.

FIG. 1 is an explanatory diagram showing an outline of a centrifugal compressor and a turbocharger according to an embodiment, and FIG. 2 is an explanatory diagram showing an outline of a centrifugal compressor according to an embodiment. The turbocharger (exhaust turbocharger) 1 according to the embodiment is provided adjacent to an internal combustion engine (not shown). The turbocharger 1 includes a centrifugal compressor 10 according to an embodiment and a turbine 2. In the turbocharger 1, the centrifugal compressor 10 and the turbine 2 are connected via a rotating shaft 3. In the turbocharger 1, when the turbine 2 is rotationally driven by the exhaust gas exhausted from an internal combustion engine (not shown), the centrifugal compressor 10 is driven by the rotating shaft 3, and the air or the like taken into the centrifugal compressor 10 from the outside is driven. The fluid is compressed and pumped to an internal combustion engine (not shown).

The centrifugal compressor 10 according to the embodiment includes a compression unit 20 and a flow rate adjusting device 30. As shown in FIG. 2, the compression unit 20 is housed in the casing 11. The compression portion 20 is connected to the rotary shaft 3 rotatably supported by the casing 11. An impeller 21 which is an impeller is provided on the rotating shaft 3. The impeller 21 has an impeller wheel 21a connected to the rotating shaft 3 and a plurality of blades 21b provided on the impeller wheel 21a at intervals along the circumferential direction of the rotating shaft 3.

The compression unit 20 has a flow path formed by the casing 11 so as to suck the fluid, compress it, and then discharge the fluid. The flow path is composed of an intake passage 22, a diffuser 23, and a discharge passage (not shown). The intake passage 22 is formed on the upstream side of the impeller 21 and communicates with the inlet 21c of the impeller 21. The intake passage 22 is provided with a suction port 22a for taking the fluid into the casing 11. Further, the intake passage 22 is provided with a plurality of inlet guide blades 31 of the flow rate adjusting device 30, which will be described later. The diffuser 23 is formed on the outer periphery of the impeller 21 and communicates with the outlet of the impeller 21. A discharge flow path (not shown) communicates with the diffuser 23 and discharges the fluid compressed by the centrifugal compressor 10 to the outside of the casing 11.

In the centrifugal compressor 10, when the rotating shaft 3 rotates with the driving of the turbine 2, the impeller 21 rotates together with the rotating shaft 3. As a result, the fluid is sucked from the suction port 22a of the intake passage 22, compressed by the impeller 21 via the plurality of inlet guide blades 31, and then decelerated by the diffuser 23 to recover the static pressure. Further, the fluid is supplied to an internal combustion engine (not shown) via a discharge flow path (not shown).

Next, the flow rate adjusting device 30 included in the centrifugal compressor 10 according to the embodiment will be described. FIG. 3 is a perspective view showing a vicinity in which a plurality of inlet guide blades are arranged in the centrifugal compressor according to the embodiment, and FIG. 4 is a perspective view showing the inlet guide blades. Although only a part of the plurality of inlet guide wings 31 is shown in FIG. 3, it is actually provided over the entire circumference of the inner wall 11a of the casing 11.

The flow rate adjusting device 30 adjusts the flow rate of the fluid supplied to the impeller 21. Further, in the present embodiment, the flow rate adjusting device 30 also has a function of applying a turning force to the fluid supplied to the impeller 21. As shown in FIG. 2, the flow rate adjusting device 30 includes a plurality of inlet guide blades 31, a drive mechanism 32, an actuator (drive unit) 33, and a control unit 34.

The plurality of inlet guide blades 31 are arranged at equal intervals along the circumferential direction of the rotation shaft 3 on the upstream side of the impeller 21 in the intake passage 22. As shown in FIGS. 2 to 4, each inlet guide wing 31 includes a wing main body 311, a pedestal 312, and a support shaft 313. In each inlet guide wing 31, the wing root 311a of the wing body 311 is fixed to one surface of the pedestal 312, and the support shaft 313 extends from the other surface of the pedestal 312. The pedestal 312 is rotatably housed in the casing 11. The support shaft 313 is rotatably housed inside the casing 11 and penetrates the casing 11 and projects to the outside of the outer wall 11b. As shown in FIGS. 2 and 3, the support shaft 313 is connected to the stator ring 32a rotatably attached to the outside of the outer wall 11b via a link mechanism 32b. The stator ring 32a and the link mechanism 32b constitute the drive mechanism 32 and are driven by power from the actuator 33. The actuator 33 is controlled by the control unit 34.

The structure of each inlet guide wing 31 will be described in more detail. As shown in FIG. 2, each inlet guide wing 31 has a wing body 311 protruding from the inner wall 11a of the casing 11 toward the rotation shaft 3 side. In the blade body 311, the blade apex 311b is located on the outer diameter side of the innermost diameter portion 21d of the inlet 21c of the impeller 21. More specifically, in the present embodiment, each inlet guide wing 31 has a protrusion length L from the inner wall 11a of the casing 11 of 5% or more and 45% or less of the inlet radius R of the impeller 21. Further, as shown in FIGS. 2 and 4, each inlet guide wing 31 is formed in a tapered shape in which the length of the chord becomes shorter as the wing body 311 goes from the wing root 311a to the wing apex 311b. The blade body 311 is formed in an arc shape in which the blade apex 311b is recessed toward the blade root 311a. Further, in the present embodiment, as shown in FIG. 4, the wing body 311 is formed so that the chord length at the wing root 311a is larger than the diameter of the pedestal 312. That is, the wing body 311 is formed so as to project outward from the pedestal 312 in the chord direction.

In the flow rate adjusting device 30 configured as described above, when the rotational force from the actuator 33 is applied to the stator ring 32a and the stator ring 32a rotates along the peripheral edge of the outer wall 11b, each link mechanism 32b presses the support shaft 313. It rotates as a center, and each support shaft 313 of all the inlet guide blades 31 rotates in conjunction with each other via each link mechanism 32b. As a result, as shown by the solid curved arrow in FIG. 2, all the inlet guide blades 31 rotate in conjunction with each other around the direction orthogonal to the rotation axis 3. In FIG. 2, the inlet guide wing 31 located on the lower side in the figure shows a state in which the wing surface 311c is positioned at the first position 51 orthogonal to the direction of the main flow F of the fluid flowing through the intake passage 22. Further, in FIG. 2, the inlet guide blade 31 located on the upper side in the figure shows a state of being positioned at the second position 52 where the blade surface 311c is horizontal with respect to the direction of the mainstream F.

Here, FIG. 5 is a schematic view showing an intake passage in a state where a plurality of inlet guide blades are positioned at the first position. FIG. 5 is a front view of the intake passage 22 as viewed from the suction port 22a side (left side in FIG. 2). The same applies to FIG. 6 described later, and in FIGS. 5 and 6, the description other than the casing 11 and the plurality of inlet guide blades 31 is omitted. Further, the number of inlet guide blades 31 shown in FIGS. 5 and 6 is an example. As shown in the figure, when the plurality of inlet guide blades 31 are located at the first position 51, the blade surfaces 311c of the adjacent ones are arranged in a row along the circumferential direction of the rotation axis 3. At this time, the wing apex 311b of each inlet guide wing 31 is connected to form a circular edge portion. As a result, when the plurality of inlet guide blades 31 are located at the first position 51, the outer diameter side of the intake passage 22 is trimmed into a circular shape, and the passage width of the intake passage 22 is narrowed. As described above, in the present embodiment, the blade body 311 is formed so as to project outward from the pedestal 312 in the chord direction. Therefore, as shown in FIG. 3, even if the pedestals 312 are separated from each other, the adjacent blade bodies 311 can be lined up in a row, and wear and malfunction due to contact between the pedestals 312 can be prevented. It should be noted that the term "consecutively lined up" includes not only the case where adjacent blade surfaces 311c are completely continuous without gaps, but also the case where gaps due to manufacturing errors are formed. Further, it is preferable that the outer surface of the wing body 311 in which adjacent objects may come into contact with each other is coated with a slip material (abreable material) made of a soft resin or the like.

On the other hand, FIG. 6 is a schematic view showing an intake passage in a state where a plurality of inlet guide blades are positioned at the second position. As shown in the figure, when the plurality of inlet guide blades 31 are located at the second position 52, each blade surface 311c of each blade body 311 is horizontal to the direction of the mainstream F, so that the outer diameter side of the intake passage 22 is It will be in the most open state.

Next, a control method of the flow rate adjusting device 30 of the centrifugal compressor 10 according to the present embodiment will be described. The control unit 34 of the flow rate adjusting device 30 acquires the flow rate of the fluid supplied to the intake passage 22 of the centrifugal compressor 10 from a control unit (not shown) that controls the entire turbocharger 1 during operation of the turbocharger 1.

When the flow rate of the acquired fluid is equal to or less than a predetermined flow rate, the control unit 34 positions the plurality of inlet guide blades 31 at the first position 51 by the actuator 33. The "predetermined flow rate" and the "second predetermined flow rate" described later correspond to various operating parameters such as the compression ratio of the fluid in the compression unit 20 when operating the centrifugal compressor 10, the turbo rotation speed, and the discharge temperature. And multiple settings. As a result, as shown in FIG. 5, the blade surfaces 311c of the plurality of inlet guide blades 31 adjacent to each other are arranged in a row along the circumferential direction of the rotation shaft 3, and the outer diameter side of the intake passage 22 is trimmed into a circular shape. To. As a result, when the flow rate of the fluid is equal to or less than the predetermined flow rate, the flow path of the intake passage 22 is narrowed, and the flow rate supplied to the impeller 21 is reduced.

Here, FIG. 7 is an explanatory diagram showing an example of an operation range in the centrifugal compressor of the present embodiment. The horizontal axis in the figure is the flow rate (volumetric flow rate) supplied to the centrifugal compressor 10, and the vertical axis is the compression ratio of the fluid in the centrifugal compressor 10. In the figure, the broken line shows the relationship in the centrifugal compressor not provided with the flow rate adjusting device 30 (not provided with the plurality of inlet guide blades 31) as a comparative example, and the solid line shows the relationship in the centrifugal compressor 10 of the present embodiment. Is shown. As shown in the figure, in the centrifugal compressor 10 of the present embodiment, since a plurality of inlet guide blades 31 are arranged in the intake passage 22, the operation range as a whole is on the small flow rate side as compared with the centrifugal compressor of the comparative example. Move to. Further, as described above, since the plurality of inlet guide blades 31 can be positioned at the first position 51 and a part of the intake passage 22 can be trimmed to narrow the passage width, the figure is larger than the centrifugal compressor of the comparative example. The range of operation is expanded only by the range shaded by.

Further, when the flow rate of the acquired fluid becomes larger than the predetermined flow rate, the control unit 34 applies a rotational force from the actuator 33 to the stator ring 32a to provide a plurality of inlet guide blades 31 via the link mechanism 32b. Rotate from 1 position 51. The control unit 34 increases the rotation angle of each inlet guide blade 31 from the first position 51 in accordance with the increase in the flow rate of the fluid. As a result, the region on the outer diameter side of the intake passage 22 trimmed by the plurality of inlet guide blades 31 is gradually opened from the state shown in FIG. 5 to the state shown in FIG.

When the flow rate of the acquired fluid is a second predetermined flow rate larger than the predetermined flow rate, the control unit 34 positions the plurality of inlet guide blades 31 at the second position 52 by the actuator 33. As a result, as shown in FIG. 6, the outer diameter side of the intake passage 22 is in the most open state. Further, when the flow rate of the acquired fluid becomes equal to or higher than the second predetermined flow rate, the control unit 34 applies a rotational force from the actuator 33 to the stator ring 32a to apply a rotational force to the plurality of inlet guide blades 31 via the link mechanism 32b. Is further rotated from the second position 52.

In this way, when the flow rate of the fluid in the intake passage 22 is larger than the predetermined flow rate, the plurality of inlet guide blades 31 are gradually rotated from the first position 51 to become the mainstream F toward the impeller 21. On the other hand, a turning force is applied in advance. 8 to 10 are schematic explanatory views for explaining the action of applying a swirling force to the mainstream of the fluid toward the impeller. In the following description, “Vc” indicated by a solid arrow in FIGS. 8 to 10 indicates the mainstream velocity of the mainstream F of the fluid flowing in the intake passage 22. “Vu” indicated by the solid arrow in FIGS. 8 to 10 indicates the rotation speed of the impeller 21. “Vw” indicated by a solid arrow in FIGS. 8 to 10 indicates the relative speed of the mainstream speed Vc with respect to the rotation speed Vu when a turning force is not applied in the direction of the mainstream F. “Vws” indicated by solid arrows in FIGS. 9 and 10 indicate the relative speed of the mainstream speed Vc with respect to the rotation speed Vu when a turning force is applied in the direction of the mainstream F. The value of the rotation speed Vu is constant.

FIG. 8 shows an example in which the flow rate of the fluid is the second predetermined flow rate, the plurality of inlet guide blades 31 are positioned at the second position 52 shown in FIG. 6, and no turning force is applied to the mainstream F. .. FIG. 9 shows an example in which a swirling force is applied to the mainstream F by a plurality of inlet guide blades 31 when the flow rate of the fluid is smaller than the second predetermined flow rate. As shown in FIG. 9, when the flow rate of the fluid is small, which is equal to or less than the second predetermined flow rate, the mainstream velocity Vc is relatively smaller than that in the example shown in FIG. Therefore, the angle of the relative velocity Vw of the mainstream F with respect to the blade surface of the blade 21b of the impeller 21 becomes larger with respect to the blade surface as shown by the broken line in the figure. As a result, the mainstream F cannot smoothly flow into the impeller 21, and the centrifugal compressor 10 may stall. In the present embodiment, as described above, when the flow rate of the fluid is smaller than the second predetermined flow rate, a plurality of inlet guide blades 31 are moved from the first position 51 to the second position 52 according to the flow rate. Rotate to a position between. As a result, as shown by the white arrows in FIG. 9, a turning force is applied to the mainstream F in advance by the plurality of inlet guide blades 31, and the angle of the relative velocity Vws is in the direction along the blade surface of the blade 21b of the impeller 21. Will be modified to.

Further, FIG. 10 shows an example in which a swirling force is applied to the mainstream F by a plurality of inlet guide blades 31 when the flow rate of the fluid is larger than the second predetermined flow rate. As shown in FIG. 10, when the flow rate of the fluid is larger than the second predetermined flow rate, the mainstream velocity Vc is relatively large as compared with the example shown in FIG. Therefore, the angle of the relative velocity Vw of the mainstream F with respect to the blade surface of the blade 21b of the impeller 21 increases in the direction opposite to the example shown in FIG. 9 with respect to the blade surface, as shown by the broken line in the figure. As a result, the mainstream F cannot smoothly flow into the impeller 21, and the centrifugal compressor 10 may stall. In the present embodiment, as described above, when the flow rate of the fluid is larger than the second predetermined flow rate, the plurality of inlet guide blades 31 are further rotated from the second position 52. As a result, as shown by the white arrows in FIG. 10, a turning force is applied to the mainstream F in advance by the plurality of inlet guide blades 31, and the angle of the relative velocity Vws is in the direction along the blade surface of the blade 21b of the impeller 21. Will be modified to. As described above, by applying an appropriate turning force in advance in the direction of the mainstream F at both the small flow rate and the large flow rate, the mainstream F smoothly flows into the impeller 21 and the centrifugal compressor 10 is used. Stall is suppressed.

As described above, in the centrifugal compressor 10 and the turbocharger 1 according to the present embodiment, a plurality of inlet guide blades 31 for applying a turning force to the fluid supplied to the impeller 21 are positioned at the first position 51, and the blades are winged. By arranging the surfaces 311c in a row along the circumferential direction of the rotation shaft 3, the outer diameter side of the intake passage 22 can be trimmed and the passage width of the intake passage 22 can be narrowed. As a result, the supply flow rate can be adjusted by using the inlet guide blade 31 for imparting the swivel blade to the fluid supplied to the impeller 21. That is, one flow rate adjusting device 30 can have both a function for applying a turning force and a function for adjusting the flow rate. Therefore, it is possible to provide a centrifugal compressor 10 having a variable supply flow rate with a simple structure and a turbocharger 1 provided with the centrifugal compressor 10.

Further, the plurality of inlet guide wings 31 have a protrusion length L from the inner wall 11a of the casing 11 of 5% or more and 45% or less of the inlet radius R of the impeller 21.

With this configuration, when a plurality of inlet guide blades 31 are positioned at the first position 51, the inlet 21c of the impeller 21 is prevented from being excessively blocked, and the fluid is stably supplied to the impeller 21 to centrifuge. The compressor 10 can be operated stably. Further, when the plurality of inlet guide blades 31 rotate from the first position 51, an appropriate turning force can be applied to the fluid.

Further, the flow rate adjusting device 30 includes an actuator (driving unit) 33 for rotating a plurality of inlet guide blades 31 and a control unit 34 for controlling the actuator 33, and the control unit 34 has a fluid flow rate of a predetermined flow rate or less. When the actuator 33 positions the plurality of inlet guide blades 31 at the first position 51 and the flow rate of the fluid is larger than the predetermined flow rate, the actuator 33 causes the plurality of inlet guide blades 31 to be the first. The rotation angle from one position 51 is increased.

With this configuration, when the flow rate supplied to the impeller 21 is small, the flow rate of the mainstream F supplied to the impeller 21 by the plurality of inlet guide blades 31 positioned at the first position 51 is increased. It can be further reduced and the operating range of the centrifugal compressor 10 can be expanded on the small flow rate side. On the other hand, when the flow rate is larger than the predetermined flow rate, the mainstream F can be smoothly guided to the impeller 21 by applying a turning force to the mainstream F by the plurality of inlet guide blades 31. As a result, the stall of the centrifugal compressor 10 can be suppressed, and stable operation of the centrifugal compressor 10 can be achieved.

Further, when the flow rate is a second predetermined flow rate larger than the predetermined flow rate, the control unit 34 uses the actuator 33 to place the plurality of inlet guide blades 31 at the second position where the blade surface 311c is horizontal with respect to the direction of the mainstream F. Positioned at 52, when the flow rate of the fluid is larger than the second predetermined flow rate, the actuator 33 increases the rotation angle of the plurality of inlet guide blades 31 from the second position 52 in accordance with the increase in the flow rate.

With this configuration, when the flow rate supplied to the impeller is larger than the predetermined flow rate and larger than the second predetermined flow rate, the blade surface 311c of the plurality of inlet guide blades 31 becomes horizontal with respect to the direction of the mainstream F. The mainstream F can be smoothly guided to the impeller 21 by further rotating from the second position 52. As a result, the stall of the centrifugal compressor 10 can be suppressed even at a large flow rate, and stable operation of the centrifugal compressor 10 can be achieved.

The number of the plurality of inlet guide blades 31 and the shape of the blade main body 311 of each inlet guide blade 31 are not limited to those shown in the present embodiment. The plurality of inlet guide blades 31 can impart a swivel blade to the fluid supplied to the impeller 21, and when the plurality of inlet guide blades 31 are located at the first position 51, the blade surfaces 311c of the adjacent ones are the rotation shaft 3 Any number and shape may be used as long as they can be lined up in a row along the circumferential direction of. For example, the blade apex 311b of the blade body 311 may be formed in a linear shape instead of an arc shape. Further, the wing body 311 may be formed so that the chord length of the wing root 311a is the same as the diameter of the pedestal 312 without protruding outward from the pedestal 312 in the chord direction. In this case, if the pedestals 312 are provided adjacent to each other, the adjacent wing bodies 311 can be lined up in a row when the first position 51 is reached.

Further, the protrusion length L of the plurality of inlet guide blades 31 can give an appropriate turning force to the fluid supplied to the impeller 21, and the intake passage 22 is wider than the width of the inlet 21c of the impeller 21. It can be of any length as long as it is not trimmed to a large extent.

Further, the structure for rotating the plurality of inlet guide blades 31 is not limited to that shown in the present embodiment, and may be any structure. For example, a drive mechanism and an actuator (drive unit) for rotating a plurality of inlet guide blades 31 may be provided one by one corresponding to each inlet guide blade 31.

Here, FIGS. 11 and 12 are explanatory views schematically showing the structure and operation of the inlet guide blade in the modified example of the flow rate adjusting device. In the flow rate adjusting device 300 as a modification, a groove portion 11c is formed in the casing 11 so as to penetrate the outer wall 11b (see FIG. 2) from the inner wall 11a (see FIG. 2). One groove portion 11c is provided corresponding to each inlet guide wing 31. The groove portion 11c is formed in an arc shape as shown in FIGS. 11 and 12. The groove portion 11c has one end 11d arranged on the downstream side of the mainstream F and the other end 11e arranged on the upstream side of the mainstream F.

The support shaft 313 is movably inserted into the groove portion 11c of each inlet guide wing 31. Further, each inlet guide wing 31 has a support shaft 313 attached to a drive mechanism (not shown) on the outside of the outer wall 11b of the casing 11. The drive mechanism moves the support shaft 313 along the groove portion 11c by a drive force from an actuator (drive portion) (not shown). The drive mechanism (not shown) and the actuator (not shown) may be operated by interlocking all the inlet guide blades 31, or may be provided one by one corresponding to each inlet guide blade 31. ..

As a result, as shown in FIG. 11, when the support shaft 313 is positioned at one end 11d of the groove portion 11c, that is, at the most side of the impeller 21, the blade surface 311c of each inlet guide wing 31 is orthogonal to the direction of the mainstream F. It is positioned at the first position 51. Further, as shown in FIG. 12, each inlet guide wing 31 has a support shaft 313 that slides and moves in the groove portion 11c via a drive mechanism by a driving force from an actuator (not shown). As a result, each inlet guide wing 31 moves in a direction away from the impeller 21 while rotating around a direction orthogonal to the rotation axis 3 as the support shaft 313 slides. At this time, in the examples shown in FIGS. 11 and 12, when the support shaft 313 is located at the center of one end 11d and the other end 11e of the groove 11c, the blade surface 311c is in the direction of the mainstream F. It will be positioned at the second position 52, which is horizontal to the relative position. That is, the plurality of inlet guide wings 31 are closest to the impeller 21 when positioned at the first position 51, and move away from the impeller 21 as they rotate from the first position 51.

With this configuration, when the plurality of inlet guide blades 31 are positioned at the first position 51 and the outer diameter side of the intake passage 22 is trimmed, the plurality of inlet guide blades 31 can be positioned at positions relatively close to the impeller 21. can. As a result, the mainstream F cut by the plurality of inlet guide blades 31 reattaches to the inner wall 11a of the intake passage 22 before reaching the impeller 21, and as a result, the flow rate supplied to the impeller 21 is not reduced. It can be suppressed. Further, it is possible to prevent the mainstream F cut by the plurality of inlet guide blades 31 from flowing back in the vicinity of the inner wall 11a. Further, when the plurality of inlet guide blades 31 rotate from the first position 51 and apply a turning force to the mainstream F, the plurality of inlet guide blades 31 are prevented from being too close to the impeller 21 so that the mainstream F is not too close. It is possible to give an appropriate turning force to the vehicle.

In the centrifugal compressor 10 according to the embodiment shown in FIG. 2, the axial positions of the rotation shafts 3 of the plurality of inlet guide blades 31 give an appropriate turning force to the fluid supplied to the impeller 21. It is possible to sufficiently reduce the flow rate supplied to the impeller 21 when the plurality of inlet guide blades 31 are positioned at the first position 51, and it is possible to prevent the backflow of the cut mainstream F. It may be a position.

1 Turbocharger 2 Turbine 3 Rotating shaft 10,100 Centrifugal compressor 11 Casing 11a Inner wall 11b Outer wall 11c Groove 11d One end 11e Other end 20 Compressor 21 Impeller 21a Impeller wheel 21b Blade 21c Inlet 21d Inner diameter 22a Diffuser 30 Flow control device 31 Inlet guide wing 311 Wing body 311a Wing root 311b Wing top 311c Wing surface 312 Pedestal 313 Support shaft 32 Drive mechanism 32a Stator ring 32b Link mechanism 33 Actuator 34 Control unit 51 1st position 52 2nd position

Claims (6)

The casing with the intake passage and
An impeller that compresses the fluid supplied from the intake passage,
A flow rate adjusting device that adjusts the flow rate of the fluid supplied to the impeller, and
Equipped with
The flow rate adjusting device is rotatably attached to the casing in the intake passage about a direction orthogonal to the rotation axis of the impeller, and imparts a swirling force to the fluid supplied to the impeller. Has multiple entrance guide wings
The plurality of inlet guide blades project from the inner wall of the casing toward the rotation axis side, and the blade apex is located on the outer diameter side of the innermost diameter portion of the inlet of the impeller.
When the blade surfaces of the plurality of inlet guide blades are located at the first position orthogonal to the direction of the main flow of the fluid, the blade surfaces of the inlet guide blades arranged adjacent to each other are the circumferences of the rotation axis. Lined up in a row along the direction,
The plurality of inlet guide blades are centrifugal compressors, wherein the protrusion length of the casing from the inner wall is 5% or more and 45% or less of the inlet radius of the impeller . The flow rate adjusting device includes a drive unit for rotating the plurality of inlet guide blades and a control unit for controlling the drive unit.
When the flow rate of the fluid is equal to or less than a predetermined flow rate, the control unit positions the plurality of inlet guide blades at the first position by the drive unit, and when the flow rate of the fluid is larger than the predetermined flow rate. The centrifugal compressor according to claim 1 , wherein the drive unit increases the rotation angle of the plurality of inlet guide blades from the first position in response to an increase in the flow rate. When the flow rate is a second predetermined flow rate larger than the predetermined flow rate, the control unit makes the plurality of inlet guide blades horizontal to the mainstream direction by the drive unit. Positioned at a position, when the flow rate of the fluid is larger than the second predetermined flow rate, the drive unit adjusts the rotation angle of the plurality of inlet guide blades from the second position in response to the increase in the flow rate. The centrifugal compressor according to claim 2 , wherein the number is increased. One of claims 1 to 3 , wherein the plurality of inlet guide blades are provided so as to be movable in the axial direction of the rotation axis, and move away from the impeller as they rotate from the first position. The centrifugal compressor according to one item. The casing with the intake passage and
An impeller that compresses the fluid supplied from the intake passage,
A flow rate adjusting device that adjusts the flow rate of the fluid supplied to the impeller, and
Equipped with
The flow rate adjusting device is rotatably attached to the casing in the intake passage about a direction orthogonal to the rotation axis of the impeller, and imparts a swirling force to the fluid supplied to the impeller. Has multiple entrance guide wings
The plurality of inlet guide blades project from the inner wall of the casing toward the rotation axis side, and the blade apex is located on the outer diameter side of the innermost diameter portion of the inlet of the impeller.
When the blade surfaces of the plurality of inlet guide blades are located at the first position orthogonal to the direction of the main flow of the fluid, the blade surfaces of the inlet guide blades arranged adjacent to each other are the circumferences of the rotation axis. Lined up in a row along the direction,
A centrifugal compressor characterized in that the plurality of inlet guide blades are provided so as to be movable in the axial direction of the rotation shaft, and are separated from the impeller as they rotate from the first position. A turbocharger comprising the centrifugal compressor according to any one of claims 1 to 5.

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