Centrifugal Compressors and Turbochargers

Abstract

This centrifugal compressor is provided with: a housing chamber which is formed in the area of a compressor housing upstream of the blades of a compressor impeller in the air intake direction; a movable member which is arranged in the housing chamber and which can move between a protruding position where the movable member protrudes into the intake flow path and a retracted position where the movable member is retracted from the intake flow path; multiple slits (340) which are formed nearer to the blades than to the housing chamber in the compressor housing, and which communicate with the intake flow path; multiple partition walls 320 which partition the slits 340 in the circumferential direction; and an outer peripheral wall 330 which connects the outer diameter ends of the multiple partition walls 320.

Description

[Technical field]

[0001] This disclosure relates to a centrifugal compressor and a turbocharger. This application claims the benefit of priority from Japanese Patent Application No. 2021-131605 filed on August 12, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] A centrifugal compressor has a compressor housing with an intake passage formed therein. A compressor impeller is disposed in the intake passage. When the flow rate of air flowing into the compressor impeller decreases, the air compressed by the compressor impeller flows back through the intake passage, causing a phenomenon called surging.

[0003] Patent Document 1 discloses a centrifugal compressor having a throttling mechanism in a compressor housing. The throttling mechanism includes a movable member. The movable member is configured to be movable between a protruding position where it protrudes into the intake air flow path and a retracted position where it retracts from the intake air flow path. The throttling mechanism reduces the flow path cross-sectional area of ​​the intake air flow path by protruding the movable member into the intake air flow path. When the movable member protrudes into the intake air flow path, air flowing backward in the intake air flow path is blocked by the movable member. By blocking the air flowing backward in the intake air flow path, surging is suppressed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Pat. No. 10,677,153 Summary of the Invention [Problem to be solved by the invention]

[0005] The air flowing back through the intake passage contains a swirling component caused by the rotation of the compressor impeller. As described in Patent Document 1, if the air flowing back through the intake passage is blocked by a movable member, the swirling component of the air flowing back can disrupt the flow near the leading edge of the compressor impeller, which can cause noise that is thought to be aerodynamic noise.

[0006] An object of the present disclosure is to provide a centrifugal compressor and a turbocharger capable of reducing noise. [Means for solving the problem]

[0007] In order to solve the above problems, a centrifugal compressor according to one aspect of the present disclosure includes a housing in which an intake air flow path is formed, a compressor impeller arranged in the intake air flow path and having a plurality of blades, an accommodation chamber formed in the housing upstream of the blades in a flow of intake air, a movable member arranged in the accommodation chamber and movable between a protruding position where the movable member protrudes into the intake air flow path and a retracted position where the movable member is retracted from the intake air flow path, a plurality of slits formed in the housing near the blades with respect to the accommodation chamber and communicating with the intake air flow path, a plurality of partition walls that circumferentially partition the plurality of slits, and an outer circumferential wall that connects outer diameter ends of the plurality of partition walls. The partition walls are disposed closer to the storage chamber than the leading edge of the blade. .

[0009] The partition walls may be inclined in the rotation direction of the compressor impeller.

[0010] The inclination angle of the multiple partition walls may be within a range of 20° to 70°, or −20° to −70° with respect to the radial direction of the compressor impeller.

[0011] In order to solve the above problem, a turbocharger according to the present disclosure includes the above centrifugal compressor. Effect of the Invention

[0012] According to the present disclosure, noise can be reduced. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic cross-sectional view of a turbocharger according to a first embodiment. [Diagram 2] FIG. 2 is an extract of the portion enclosed by the dashed line in FIG. [Diagram 3] FIG. 3 is a schematic perspective view of the annular member according to the first embodiment. [Figure 4] FIG. 4 is an exploded perspective view of members that constitute the link mechanism. [Diagram 5] FIG. 5 is a cross-sectional view taken along line IV-IV in FIG. [Figure 6] FIG. 6 is a first diagram for explaining the operation of the link mechanism. [Figure 7] FIG. 7 is a second diagram for explaining the operation of the link mechanism. [Figure 8] FIG. 8 is a third diagram for explaining the operation of the link mechanism. [Figure 9] FIG. 9 is a schematic front view of the annular member according to the second embodiment. [Figure 10] FIG. 10 is a diagram for explaining the relationship between the inclination angle of the partition wall and the compressor efficiency. [Figure 11] FIG. 11 is a schematic front view of an annular member according to the third embodiment. [Figure 12] FIG. 12 is a schematic front view of an annular member according to the fourth embodiment. [Figure 13] FIG. 13 is a diagram for explaining the relationship between the type of partition wall and the compressor efficiency. [Figure 14] FIG. 14 is a schematic front view of the annular member according to the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values ​​shown in the embodiment are merely examples for ease of understanding, and do not limit the present disclosure unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanation. Elements not directly related to the present disclosure are not illustrated.

[0015] (First embodiment) FIG. 1 is a schematic cross-sectional view of a turbocharger TC according to the first embodiment. The direction of the arrow L shown in FIG. 1 will be described as the left side of the turbocharger TC. The direction of the arrow R shown in FIG. 1 will be described as the right side of the turbocharger TC. Of the turbocharger TC, the compressor housing 100 side described later functions as a centrifugal compressor CC. In the following, the centrifugal compressor CC will be described as being driven by a turbine impeller 8 described later. However, without being limited thereto, the centrifugal compressor CC may be driven by an engine (not shown) or an electric motor (motor) (not shown). In this way, the centrifugal compressor CC may be incorporated in a device other than the turbocharger TC, or may be a standalone unit.

[0016] As shown in Fig. 1, the turbocharger TC includes a turbocharger body 1. The turbocharger body 1 includes a bearing housing 2, a turbine housing 4, a compressor housing (housing) 100, and a link mechanism 200. Details of the link mechanism 200 will be described later. The turbine housing 4 is connected to the left side of the bearing housing 2 by a fastening bolt 3. The compressor housing 100 is connected to the right side of the bearing housing 2 by a fastening bolt 5.

[0017] The bearing housing 2 is formed with an accommodation hole 2a. The accommodation hole 2a penetrates the bearing housing 2 in the left-right direction of the turbocharger TC. A bearing 6 is disposed in the accommodation hole 2a. In FIG. 1, a full-floating bearing is shown as an example of the bearing 6. However, the bearing 6 may be another radial bearing such as a semi-floating bearing or a rolling bearing. A part of a shaft 7 is disposed in the accommodation hole 2a. The shaft 7 is rotatably supported by the bearing 6. A turbine impeller 8 is provided at the left end of the shaft 7. The turbine impeller 8 is rotatably housed in the turbine housing 4. A compressor impeller 9 is provided at the right end of the shaft 7. The compressor impeller 9 is rotatably housed in the compressor housing 100. In the present disclosure, the "rotational axis direction", "radial direction", and "circumferential direction" of the shaft 7, the turbine impeller 8, and the compressor impeller 9 may be simply referred to as the "rotational axis direction", the "radial direction", and the "circumferential direction", respectively. The compressor impeller 9 has a plurality of long blades 9a and a plurality of short blades 9b formed on the outer circumferential surface of the hub. The plurality of long blades 9a and short blades 9b are formed alternately and spaced apart in the circumferential direction. The plurality of long blades 9a and short blades 9b are formed at equal intervals in the circumferential direction. The leading edge LE of the long blade 9a is located on the side away from the bearing housing 2 with respect to the leading edge LE of the short blade 9b. In other words, the leading edge LE of the short blade 9b is located on the side closer to the bearing housing 2 with respect to the leading edge LE of the long blade 9a. In this embodiment, the compressor impeller 9 has the long blade 9a and the short blade 9b, but is not limited thereto, and the compressor impeller 9 may have only one of the long blade 9a and the short blade 9b.

[0018] An intake port 10 is formed in the compressor housing 100. The intake port 10 opens to the right side of the turbocharger TC. The intake port 10 is connected to an air cleaner (not shown). A diffuser passage 11 is formed between the bearing housing 2 and the compressor housing 100. The diffuser passage 11 pressurizes air. The diffuser passage 11 is formed in an annular shape from the inside to the outside in the radial direction. The diffuser passage 11 is connected to the intake port 10 via the compressor impeller 9 on the inside in the radial direction.

[0019] Further, the compressor housing 100 is formed with a compressor scroll passage 12. The compressor scroll passage 12 is located, for example, radially outward of the compressor impeller 9. The compressor scroll passage 12 communicates with an intake port of an engine (not shown) and a diffuser passage 11. When the compressor impeller 9 rotates, air is taken into the compressor housing 100 from the intake port 10. The taken-in air is pressurized and accelerated in the process of flowing between the blades of the compressor impeller 9. The pressurized and accelerated air is further pressurized in the diffuser passage 11 and the compressor scroll passage 12. The pressurized air flows out from a discharge port (not shown) and is led to the intake port of the engine.

[0020] In this manner, the turbocharger TC includes a centrifugal compressor CC that compresses the fluid by utilizing centrifugal force. The centrifugal compressor CC includes a compressor housing 100, a compressor impeller 9, and a link mechanism 200, which will be described later.

[0021] An exhaust port 13 is formed in the turbine housing 4. The exhaust port 13 opens to the left side of the turbocharger TC. The exhaust port 13 is connected to an exhaust gas purification device (not shown). A communication passage 14 and a turbine scroll passage 15 are formed in the turbine housing 4. The turbine scroll passage 15 is located radially outward of the turbine impeller 8. The communication passage 14 is located between the turbine impeller 8 and the turbine scroll passage 15.

[0022] The turbine scroll passage 15 communicates with a gas inlet (not shown). Exhaust gas discharged from an exhaust manifold of an engine (not shown) is introduced to the gas inlet. The communication passage 14 communicates the turbine scroll passage 15 with the exhaust port 13. The exhaust gas introduced from the gas inlet to the turbine scroll passage 15 is introduced to the exhaust port 13 through the communication passage 14 and between the blades of the turbine impeller 8. The exhaust gas rotates the turbine impeller 8 during its flow process.

[0023] The rotational force of the turbine impeller 8 is transmitted to the compressor impeller 9 via the shaft 7. As described above, air is pressurized by the rotational force of the compressor impeller 9 and is guided to the intake port of the engine.

[0024] Fig. 2 is an extracted view of the dashed line portion in Fig. 1. As shown in Fig. 2, the compressor housing 100 includes a first housing member 110 and a second housing member 120. The first housing member 110 is located to the right (the side away from the bearing housing 2) of the second housing member 120 in Fig. 2. The second housing member 120 is connected to the bearing housing 2. The first housing member 110 is connected to the second housing member 120 in the rotation axis direction.

[0025] The first housing member 110 has a roughly cylindrical shape. A through hole 111 is formed in the first housing member 110. The first housing member 110 has an end face 112 on a side adjacent to (connected with) the second housing member 120. The first housing member 110 also has an end face 113 on a side away from the second housing member 120. An intake port 10 is formed in the end face 113. The through hole 111 extends from the end face 112 to the end face 113 (intake port 10) along the rotation axis direction. That is, the through hole 111 penetrates the first housing member 110 in the rotation axis direction. The through hole 111 has the intake port 10 in the end face 113.

[0026] The through hole 111 has a parallel portion 111a and a reduced diameter portion 111b. The parallel portion 111a is located closer to the end face 113 than the reduced diameter portion 111b. The inner diameter of the parallel portion 111a is approximately constant along the rotation axis direction. The reduced diameter portion 111b is located closer to the end face 112 than the parallel portion 111a. The reduced diameter portion 111b is continuous with the parallel portion 111a. The inner diameter of the portion of the reduced diameter portion 111b that is continuous with the parallel portion 111a is approximately equal to the inner diameter of the parallel portion 111a. The inner diameter of the reduced diameter portion 111b becomes smaller as it becomes farther away from the parallel portion 111a (closer to the end face 112).

[0027] A cutout portion 112a is formed in the end face 112. The cutout portion 112a is recessed from the end face 112 toward the end face 113. The cutout portion 112a is formed in the outer periphery of the end face 112. The cutout portion 112a has, for example, a roughly annular shape when viewed from the rotation axis direction.

[0028] Further, an accommodation chamber AC is formed in the end surface 112. The accommodation chamber AC is formed in the first housing member 110 closer to the intake port 10 than the leading edge LE of the full blade 9a of the compressor impeller 9. The accommodation chamber AC includes an accommodation groove 112b, a bearing hole 112d, and an accommodation hole 115 (see FIG. 4), which will be described later.

[0029] The accommodating groove 112b is formed in the end face 112. The accommodating groove 112b is located between the cutout portion 112a and the through hole 111. The accommodating groove 112b is recessed from the end face 112 toward the end face 113. The accommodating groove 112b has, for example, a roughly annular shape when viewed from the rotation axis direction. The accommodating groove 112b communicates with the through hole 111 on the radially inner side.

[0030] A bearing hole 112d is formed in a wall surface 112c of the housing groove 112b on the side of the end surface 113. The bearing hole 112d extends in the direction of the rotation axis from the wall surface 112c toward the end surface 113. Two bearing holes 112d are provided spaced apart in the rotation direction. The two bearing holes 112d are disposed at positions offset by 180 degrees in the rotation direction.

[0031] A through hole 121 is formed in the second housing member 120. The second housing member 120 has an end face 122 on a side adjacent to (connected to) the first housing member 110. The second housing member 120 also has an end face 123 on a side away from the first housing member 110 (the side connected to the bearing housing 2). The through hole 121 extends from the end face 122 to the end face 123 along the rotational axis direction. In other words, the through hole 121 penetrates the second housing member 120 in the rotational axis direction.

[0032] A recessed portion 300 recessed radially outward is formed in the through hole 121. The recessed portion 300 does not radially penetrate the second housing member 120, but is configured as a non-penetrating groove. The radial inner side of the recessed portion 300 communicates with the intake passage 130. The recessed portion 300 is formed near the blades 9a, 9b of the compressor impeller 9 with respect to the accommodation chamber AC. An annular member 310 is disposed in the recessed portion 300.

[0033] The width of the annular member 310 in the rotational axis direction is approximately equal to the width of the recessed portion 300 in the rotational axis direction. However, without being limited thereto, the width of the annular member 310 in the rotational axis direction may be smaller than the width of the recessed portion 300 in the rotational axis direction. For example, the width of the annular member 310 in the rotational axis direction may be half the width of the recessed portion 300 in the rotational axis direction. This makes it easier to assemble the annular member 310 into the recessed portion 300, and improves the ease of assembly of the centrifugal compressor CC.

[0034] The recessed portion 300 is formed closer to the accommodation chamber AC than the leading edges LE of the full blade 9a and the short blade 9b of the compressor impeller 9. Specifically, the recessed portion 300 is formed between the leading edge LE of the full blade 9a and the accommodation chamber AC. However, the present invention is not limited to this, and the recessed portion 300 may be disposed on the opposite side of the accommodation chamber AC with respect to the leading edge LE of the full blade 9a. For example, the recessed portion 300 may be disposed between the leading edge LE of the full blade 9a and the leading edge LE of the short blade 9b, or may be disposed closer to the bearing housing 2 than the leading edge LE of the short blade 9b. Moreover, the recessed portion 300 may be disposed at a position radially opposed to the leading edge LE of the full blade 9a, or may be disposed at a position radially opposed to the leading edge LE of the short blade 9b.

[0035] A partition wall 302 is provided between the recessed portion 300 and the storage chamber AC. In other words, the recessed portion 300 and the storage chamber AC are separated from each other in the rotation axis direction. However, this is not limited thereto, and the recessed portion 300 and the storage chamber AC may be adjacent to each other in the rotation axis direction and communicate with each other.

[0036] Fig. 3 is a schematic perspective view of an annular member 310 according to the first embodiment. As shown in Fig. 3, the annular member 310 includes a plurality of partition walls 320 and an outer peripheral wall 330. The plurality of partition walls 320 are arranged at equal intervals in the circumferential direction. However, the present invention is not limited to this, and the plurality of partition walls 320 may be arranged at unequal intervals in the circumferential direction.

[0037] The multiple partition walls 320 extend radially inward from the outer circumferential wall 330. The multiple partition walls 320 divide the internal space of the recessed portion 300 in the circumferential direction. As a result, multiple slits 340 extending in the radial direction are formed between the multiple partition walls 320. The multiple partition walls 320 divide the multiple slits 340 in the circumferential direction.

[0038] The circumferential width of the partition wall 320 is constant in the radial direction. However, without being limited thereto, the circumferential width of the partition wall 320 may vary in the radial direction. For example, the circumferential width of the partition wall 320 may gradually decrease toward the radially inner side. However, without being limited thereto, the circumferential width of the partition wall 320 may gradually increase toward the radially inner side.

[0039] The outer peripheral wall 330 connects outer diameter ends of the multiple partition walls 320. As a result, the radial outside of the multiple slits 340 is defined by the outer peripheral wall 330. In this manner, the multiple slits 340 are defined in the circumferential direction by the multiple partition walls 320, and are defined on the radial outside by the outer peripheral wall 330. The radial inside of the multiple slits 340 communicates with the intake flow path 130.

[0040] Returning to FIG. 2, the inner diameter of the through hole 121 at the end near the end face 122 is approximately equal to the inner diameter of the through hole 111 at the end near the end face 112. In other words, the inner diameter of the partition wall 302 is approximately equal to the inner diameter of the through hole 111 at the end near the end face 112. A shroud portion 121a is formed on the inner wall of the through hole 121. The shroud portion 121a faces the blades 9a, 9b of the compressor impeller 9 from the outside in the radial direction. The outer diameter of the compressor impeller 9 increases as it moves away from the leading edge LE of the full blade 9a of the compressor impeller 9 in the rotation axis direction. The inner diameter of the shroud portion 121a increases as it moves away from the end face 122 (as it moves closer to the end face 123).

[0041] An accommodating groove 122a is formed in the end face 122. The accommodating groove 122a is recessed from the end face 122 toward the end face 123. When viewed from the rotation axis direction, the accommodating groove 122a is, for example, roughly annular. The first housing member 110 is inserted into the accommodating groove 122a. The end face 112 of the first housing member 110 abuts against a wall surface 122b of the accommodating groove 122a that is parallel to the end face 123. At this time, an accommodating chamber AC is formed between the first housing member 110 (wall surface 112c) and the second housing member 120 (wall surface 122b).

[0042] The through hole 111 of the first housing member 110 and the through hole 121 of the second housing member 120 form an intake passage 130. In this manner, the intake passage 130 is formed in the compressor housing 100. The intake passage 130 extends from an air cleaner (not shown) through the intake port 10 to the diffuser passage 11. The air cleaner side (the intake port 10 side) of the intake passage 130 is the upstream side in the flow of intake air, and the diffuser passage 11 side of the intake passage 130 is the downstream side in the flow of intake air.

[0043] The compressor impeller 9 is disposed in the intake passage 130. The cross-sectional shape of the intake passage 130 (through holes 111, 121) perpendicular to the rotation axis direction is, for example, a circle centered on the rotation axis of the compressor impeller 9. However, the cross-sectional shape of the intake passage 130 is not limited thereto, and may be, for example, an ellipse.

[0044] A sealant (not shown) is disposed in the cutout portion 112a of the first housing member 110. The sealant reduces the amount of air flowing through the gap between the first housing member 110 and the second housing member 120. However, the cutout portion 112a and the sealant are not essential.

[0045] Fig. 4 is an exploded perspective view of members constituting the link mechanism 200. In Fig. 4, only the first housing member 110 of the compressor housing 100 is shown. As shown in Fig. 4, the link mechanism 200 includes the first housing member 110, a first movable member 210, a second movable member 220, a connecting member 230, and a rod 240. Hereinafter, the first movable member 210 and the second movable member 220 are also collectively referred to as movable members 210, 220. The link mechanism 200 is disposed closer to the intake port 10 of the intake passage 130 (upstream side) than the long blade 9a of the compressor impeller 9 in the rotational axis direction.

[0046] The first movable member 210 is disposed in the accommodation groove 112b (accommodation chamber AC). Specifically, the first movable member 210 is disposed between a wall surface 112c of the accommodation groove 112b and a wall surface 122b of the accommodation groove 122a (see FIG. 2) in the rotation axis direction. The first movable member 210 has an opposing surface S1 that faces the wall surface 112c of the accommodation groove 112b, and an opposing surface S2 that faces the wall surface 122b of the accommodation groove 122a. The first movable member 210 has a main body portion B1. The main body portion B1 includes a curved portion 211 and an arm portion 212.

[0047] The curved portion 211 extends in the circumferential direction. The curved portion 211 has a roughly semicircular arc shape. One end face 211a and the other end face 211b in the circumferential direction of the curved portion 211 extend parallel to the radial direction and the rotation axis direction. However, the one end face 211a and the other end face 211b may be inclined with respect to the radial direction and the rotation axis direction.

[0048] An arm portion 212 is provided on one end surface 211a of the curved portion 211. The arm portion 212 extends radially outward from an outer circumferential surface 211c of the curved portion 211. The arm portion 212 also extends in a direction inclined relative to the radial direction (toward the second movable member 220).

[0049] The second movable member 220 is disposed in the accommodation groove 112b (accommodation chamber AC). Specifically, the second movable member 220 is disposed between a wall surface 112c of the accommodation groove 112b and a wall surface 122b (see FIG. 2) of the accommodation groove 122a in the rotation axis direction. The second movable member 220 has an opposing surface S1 that faces the wall surface 112c of the accommodation groove 112b, and an opposing surface S2 that faces the wall surface 122b of the accommodation groove 122a. The second movable member 220 has a main body portion B2. The main body portion B2 includes a curved portion 221 and an arm portion 222.

[0050] The curved portion 221 extends in the circumferential direction. The curved portion 221 has a roughly semicircular arc shape. One end face 221a and the other end face 221b of the curved portion 221 in the circumferential direction extend parallel to the radial direction and the rotation axis direction. However, the one end face 221a and the other end face 221b may be inclined with respect to the radial direction and the rotation axis direction.

[0051] An arm portion 222 is provided on one end surface 221a of the curved portion 221. The arm portion 222 extends radially outward from an outer circumferential surface 221c of the curved portion 221. The arm portion 222 also extends in a direction inclined relative to the radial direction (toward the first movable member 210).

[0052] The curved portion 211 faces the curved portion 221 across the rotation center (intake flow path 130) of the compressor impeller 9. One end surface 211a of the curved portion 211 faces the other end surface 221b of the curved portion 221 in the circumferential direction. The other end surface 211b of the curved portion 211 faces the one end surface 221a of the curved portion 221 in the circumferential direction. As will be described in detail later, the first movable member 210 and the second movable member 220 are configured such that the curved portions 211, 221 are movable in the radial direction.

[0053] The connecting member 230 connects the first movable member 210 and the second movable member 220. The connecting member 230 is located closer to the intake port 10 than the first movable member 210 and the second movable member 220. The connecting member 230 has a roughly arc shape. The connecting member 230 has a first bearing hole 231 formed at one end in the circumferential direction and a second bearing hole 232 formed at the other end. The first bearing hole 231 and the second bearing hole 232 open to an end face 233 of the connecting member 230 near the first movable member 210 and the second movable member 220. The first bearing hole 231 and the second bearing hole 232 extend in the rotation axis direction. Here, the first bearing hole 231 and the second bearing hole 232 are non-through holes. However, the first bearing hole 231 and the second bearing hole 232 may penetrate the connecting member 230 in the rotation axis direction.

[0054] A rod connecting portion 234 is formed in the connecting member 230 between the first bearing hole 231 and the second bearing hole 232. The rod connecting portion 234 is formed in an end face 235 of the connecting member 230 on the side opposite to the first movable member 210 and the second movable member 220. The rod connecting portion 234 protrudes from the end face 235 in the rotation axis direction. The rod connecting portion 234 has, for example, a roughly cylindrical shape.

[0055] The rod 240 has a roughly cylindrical shape. The rod 240 has a flat portion 241 formed at one end and a connecting portion 243 formed at the other end. The flat portion 241 extends in a plane direction roughly perpendicular to the rotation axis direction. A bearing hole 242 opens in the flat portion 241. The bearing hole 242 extends in the rotation axis direction. The connecting portion 243 has a connecting hole 243a. An actuator described later is connected to the connecting portion 243 (connecting hole 243a). The bearing hole 242 may be, for example, an elongated hole whose length in the direction perpendicular to the rotation axis direction and the axial direction of the rod 240 (left-right direction in FIG. 6 described later) is longer than the axial length of the rod 240.

[0056] In the rod 240, a rod large diameter portion 244 and two rod small diameter portions 245 are formed between the flat portion 241 and the connecting portion 243. The rod large diameter portion 244 is disposed between the two rod small diameter portions 245. Of the two rod small diameter portions 245, the rod small diameter portion 245 near the flat portion 241 connects the rod large diameter portion 244 and the flat portion 241. Of the two rod small diameter portions 245, the rod small diameter portion 245 near the connecting portion 243 connects the rod large diameter portion 244 and the connecting portion 243. The outer diameter of the rod large diameter portion 244 is larger than the outer diameters of the two rod small diameter portions 245.

[0057] An insertion hole 114 is formed in the first housing member 110. One end 114a of the insertion hole 114 opens to the outside of the first housing member 110. The insertion hole 114 extends, for example, in a plane perpendicular to the rotation axis direction. The insertion hole 114 is located radially outward of the through hole 111 (air intake flow path 130). A flat portion 241 of a rod 240 is inserted into the insertion hole 114. The rod large diameter portion 244 is guided by the inner wall surface of the insertion hole 114. Movement of the rod 240 is restricted in any direction other than the central axis direction of the insertion hole 114 (the central axis direction of the rod 240).

[0058] An accommodating hole 115 is formed in the first housing member 110. The accommodating hole 115 opens to a wall surface 112c of the accommodating groove 112b. The accommodating hole 115 is recessed from the wall surface 112c toward the intake port 10. The accommodating hole 115 is located on a side farther away from the intake port 10 (closer to the second housing member 120) than the insertion hole 114. The accommodating hole 115 is roughly arc-shaped when viewed from the rotation axis direction. The accommodating hole 115 extends circumferentially longer than the connecting member 230. The accommodating hole 115 is circumferentially spaced from the bearing hole 112d.

[0059] A communication hole 116 is formed in the first housing member 110. The communication hole 116 communicates between the insertion hole 114 and the accommodation hole 115. The communication hole 116 is formed in approximately the middle portion of the accommodation hole 115 in the circumferential direction. The communication hole 116 is, for example, an elongated hole extending approximately parallel to the extension direction of the insertion hole 114. The communication hole 116 has a width in the longitudinal direction (extension direction) larger than its width in the lateral direction (direction perpendicular to the extension direction). The width of the communication hole 116 in the lateral direction is larger than the outer diameter of the rod connection portion 234 of the connecting member 230.

[0060] The connecting member 230 is accommodated in the accommodation hole 115 (accommodation chamber AC). In this manner, the first movable member 210, the second movable member 220, and the connecting member 230 are disposed in the accommodation chamber AC formed in the first housing member 110. The accommodation hole 115 is longer in the circumferential direction and larger in the radial direction than the connecting member 230. Therefore, the connecting member 230 is allowed to move within the accommodation hole 115 in a planar direction perpendicular to the rotation axis direction.

[0061] The rod connecting part 234 is inserted from the communicating hole 116 into the insertion hole 114. A flat surface part 241 of a rod 240 is inserted into the insertion hole 114. A bearing hole 242 of the flat surface part 241 faces the communicating hole 116. The rod connecting part 234 is inserted into (connected to) the bearing hole 242. The rod connecting part 234 is supported by the bearing hole 242.

[0062] Fig. 5 is a cross-sectional view taken along line VV in Fig. 2. As indicated by the dashed line in Fig. 5, the first movable member 210 has a connecting shaft portion 213 and a rotating shaft portion 214. The connecting shaft portion 213 and the rotating shaft portion 214 protrude in the rotation axis direction from an opposing surface S1 (see Fig. 2) of the first movable member 210 that faces the wall surface 112c. The connecting shaft portion 213 and the rotating shaft portion 214 extend toward the rear of the paper in Fig. 5. The rotating shaft portion 214 extends parallel to the connecting shaft portion 213. The connecting shaft portion 213 and the rotating shaft portion 214 are roughly cylindrical in shape.

[0063] The outer diameter of the connecting shaft portion 213 is smaller than the inner diameter of the first bearing hole 231 of the connecting member 230. The connecting shaft portion 213 is inserted into the first bearing hole 231. The connecting shaft portion 213 is rotatably supported in the first bearing hole 231. The outer diameter of the rotating shaft portion 214 is smaller than the inner diameter of the bearing hole 112d of the first housing member 110. The rotating shaft portion 214 is inserted into the bearing hole 112d on the vertically upper side (the side close to the rod 240) of the two bearing holes 112d. The rotating shaft portion 214 is rotatably supported in the bearing hole 112d. The rotating shaft portion 214 connects the first movable member 210 and the wall surface 112c facing the first movable member 210 in the rotation axis direction.

[0064] The second movable member 220 has a connecting shaft portion 223 and a rotating shaft portion 224. The connecting shaft portion 223 and the rotating shaft portion 224 protrude in the rotation axis direction from an opposing surface S1 (see FIG. 2) of the second movable member 220 that faces the wall surface 112c. The connecting shaft portion 223 and the rotating shaft portion 224 extend toward the rear of the page in FIG. 4. The rotating shaft portion 224 extends parallel to the connecting shaft portion 223. The connecting shaft portion 223 and the rotating shaft portion 224 are roughly cylindrical in shape.

[0065] The outer diameter of the connecting shaft portion 223 is smaller than the inner diameter of the second bearing hole 232 of the connecting member 230. The connecting shaft portion 223 is inserted into the second bearing hole 232. The connecting shaft portion 223 is rotatably supported in the second bearing hole 232. The outer diameter of the rotating shaft portion 224 is smaller than the inner diameter of the bearing hole 112d of the first housing member 110. The rotating shaft portion 224 is inserted into the bearing hole 112d on the vertically lower side (the side away from the rod 240) of the two bearing holes 112d. The rotating shaft portion 224 is rotatably supported in the bearing hole 112d. The rotating shaft portion 224 connects the second movable member 220 and the wall surface 112c facing the second movable member 220 in the rotation axis direction.

[0066] In this way, the link mechanism 200 is configured as a four-joint link mechanism. The four links (joints) are the first movable member 210, the second movable member 220, the first housing member 110, and the connecting member 230. Since the link mechanism 200 is configured as a four-joint link mechanism, it becomes a limited chain with one degree of freedom and is easy to control.

[0067] Fig. 6 is a first diagram for explaining the operation of link mechanism 200. In the following Figs. 6, 7 and 8, the link mechanism 200 is shown as viewed from the intake port 10. As shown in Fig. 6, one end of a drive shaft 251 of an actuator 250 is connected to a connecting portion 243 of a rod 240.

[0068] 6, first movable member 210 and second movable member 220 abut against each other. At this time, as shown in FIGS. 2 and 5, protruding portion 215, which is the radially inner portion of first movable member 210, protrudes (is exposed) into intake flow path 130. Protruding portion 225, which is the radially inner portion of second movable member 220, protrudes (is exposed) into intake flow path 130. The positions of first movable member 210 and second movable member 220 at this time are referred to as protruding positions (or throttling positions).

[0069] 6, at the protruding position, circumferential ends 215a, 215b of protruding portion 215 abut against circumferential ends 225a, 225b of protruding portion 225. Protruding portion 215 and protruding portion 225 form an annular hole 260. The inner diameter of annular hole 260 is smaller than the inner diameter of the portion of intake flow path 130 from which protruding portions 215, 225 protrude. The inner diameter of annular hole 260 is smaller than the inner diameter of any portion of intake flow path 130, for example.

[0070] Fig. 7 is a second diagram for explaining the operation of link mechanism 200. Fig. 8 is a third diagram for explaining the operation of link mechanism 200. Actuator 250 linearly moves rod 240 in a direction intersecting the rotation axis direction (up and down direction in Figs. 7 and 8). Rod 240 moves upward from the state shown in Fig. 6. The amount of movement of rod 240 in the arrangement of Fig. 8 relative to the arrangement of Fig. 6 is greater than that in Fig. 7.

[0071] When the rod 240 moves, the connecting member 230 moves upward in Figures 7 and 8 via the rod connecting part 234. At this time, the connecting member 230 is allowed to rotate around the rod connecting part 234. Also, there is a slight play in the inner diameter of the bearing hole 242 of the rod 240 with respect to the outer diameter of the rod connecting part 234. Therefore, the connecting member 230 is allowed to move slightly in a planar direction perpendicular to the rotation axis direction.

[0072] As described above, the link mechanism 200 is a four-bar link mechanism. The connecting member 230, the first movable member 210, and the second movable member 220 exhibit one degree of freedom of movement relative to the first housing member 110. Specifically, the connecting member 230 rotates slightly counterclockwise in Figures 7 and 8 and moves slightly in the left-right direction within the above-mentioned allowable range.

[0073] Of the first movable member 210, the rotating shaft portion 214 is supported by the first housing member 110. Movement of the rotating shaft portion 214 in a planar direction perpendicular to the rotation axis direction is restricted. The connecting shaft portion 213 is supported by the connecting member 230. Since movement of the connecting member 230 is permitted, the connecting shaft portion 213 is provided so as to be movable in a planar direction perpendicular to the rotation axis direction. As a result, in conjunction with movement of the connecting member 230, the first movable member 210 rotates in the clockwise direction in FIGS. 7 and 8 around the rotating shaft portion 214 as the center of rotation.

[0074] Similarly, of the second movable member 220, the rotating shaft portion 224 is supported by the first housing member 110. Movement of the rotating shaft portion 224 in a planar direction perpendicular to the rotation axis direction is restricted. The connecting shaft portion 223 is supported by the connecting member 230. Since movement of the connecting member 230 is permitted, the connecting shaft portion 223 is provided so as to be movable in a planar direction perpendicular to the rotation axis direction. As a result, in conjunction with movement of the connecting member 230, the second movable member 220 rotates in the clockwise direction in FIGS. 7 and 8 around the rotating shaft portion 224 as the center of rotation.

[0075] Thus, the first movable member 210 and the second movable member 220 move in a direction away from each other in the order of Figs. 7 and 8. The protrusions 215 and 225 move radially outward from the protruding position (retracted position). In the retracted position, for example, the protrusions 215 and 225 are flush with the inner wall surface of the intake passage 130 or are positioned radially outward from the inner wall surface of the intake passage 130. When moving from the retracted position to the protruding position, the first movable member 210 and the second movable member 220 approach each other and abut against each other in the order of Figs. 8, 7, and 6. In this way, the first movable member 210 and the second movable member 220 switch between the protruding position and the retracted position depending on the rotation angle about the rotating shafts 214 and 224 as the rotation center.

[0076] In this manner, the first movable member 210 and the second movable member 220 are configured to be movable between a protruding position where they protrude into the intake passage 130 and a retracted position where they are retracted from the intake passage 130. In this embodiment, the first movable member 210 and the second movable member 220 move in the radial direction. However, without being limited thereto, the first movable member 210 and the second movable member 220 may rotate around the rotation axis of the compressor impeller 9 (in the circumferential direction). For example, the first movable member 210 and the second movable member 220 may be shutter blades having two or more blades.

[0077] When the first movable member 210 and the second movable member 220 are located at the retracted position, they do not protrude into the intake air flow path 130, so that the pressure loss of the intake air (air) flowing through the intake air flow path 130 can be reduced.

[0078] 2, when in the protruding position, the protruding portions 215, 225 of the first movable member 210 and the second movable member 220 are disposed in the intake passage 130. When the first movable member 210 and the second movable member 220 are positioned in the protruding position, the flow path cross-sectional area of ​​the intake passage 130 becomes smaller.

[0079] As the flow rate of air flowing into the compressor impeller 9 decreases, the air compressed by the compressor impeller 9 may flow backward through the intake passage 130 (that is, air may flow from the downstream side to the upstream side).

[0080] 2, when the first movable member 210 and the second movable member 220 are located in the protruding position, the protruding portions 215, 225 are located radially inward of the outermost diameter end of the leading edge LE of the full blade 9a of the compressor impeller 9. As a result, air flowing back through the intake passage 130 is blocked by the protruding portions 215, 225. Therefore, the first movable member 210 and the second movable member 220 can suppress the backflow of air in the intake passage 130.

[0081] In addition, since the flow passage cross-sectional area of ​​the intake passage 130 is reduced, the flow velocity of the air flowing into the compressor impeller 9 is increased. As a result, the occurrence of surging in the centrifugal compressor CC can be suppressed. That is, the centrifugal compressor CC of this embodiment can expand the operating region to the small flow rate side by holding the first movable member 210 and the second movable member 220 in the protruding position.

[0082] In this manner, the first movable member 210 and the second movable member 220 are configured as throttling members that throttling the intake flow path 130. That is, in this embodiment, the link mechanism 200 is configured as a throttling mechanism that throttling the intake flow path 130. The first movable member 210 and the second movable member 220 can change the flow path cross-sectional area of ​​the intake flow path 130 by driving the link mechanism 200.

[0083] The air flowing backward in the intake passage 130 contains a swirling flow component caused by the rotation of the compressor impeller 9. When the air flowing backward in the intake passage 130 is blocked by the movable members 210, 220, the swirling flow component of the backward flowing air disturbs the flow near the leading edge LE of the full blade 9a of the compressor impeller 9, which may generate noise thought to be aerodynamic noise.

[0084] In this embodiment, a recessed portion 300 is formed closer to the blades 9a, 9b of the compressor impeller 9 than the accommodation chamber AC in which the movable members 210, 220 are arranged, and an annular member 310 is arranged in the recessed portion 300. The annular member 310 includes a plurality of partition walls 320 and an outer circumferential wall 330. In addition, a plurality of slits 340 are formed between the plurality of partition walls 320, and the plurality of slits 340 communicate with the intake passage 130 on the radially inner side.

[0085] Therefore, the air flowing backward in the intake passage 130 is introduced into the plurality of slits 340 and collides with the plurality of partition walls 320, thereby reducing the swirling flow component. In addition, the outer diameter ends of the plurality of slits 340 are closed by the outer peripheral wall 330. Therefore, the air flow that passes through the plurality of slits 340 and reaches the outer diameter end is blocked by the outer peripheral wall 330, and the swirling flow of the air introduced into the plurality of slits 340 inevitably comes into contact with the plurality of partition walls 320. This makes it possible to efficiently reduce the swirling flow component of the air introduced into the plurality of slits 340. As a result, noise caused by the swirling flow component of the air flowing backward in the intake passage 130 is reduced.

[0086] In the first embodiment, an example has been described in which the recessed portion 300 is formed in the second housing member 120, and the annular member 310, which is separate from the second housing member 120, is disposed in the recessed portion 300. However, the present invention is not limited to this, and the annular member 310 may be configured integrally with the second housing member 120. In this case, a plurality of slits 340 communicating with the intake passage 130 are directly formed in the second housing member 120 near the blades 9a, 9b of the compressor impeller 9 with respect to the accommodation chamber AC. Similarly, a plurality of partition walls 320 that partition the plurality of slits 340 in the circumferential direction, and an outer circumferential wall 330 that connects the outer diameter ends of the plurality of partition walls 320 are directly formed in the second housing member 120.

[0087] The multiple partition walls 320, the outer peripheral wall 330, and the multiple slits 340 are formed closer to the accommodation chamber AC than the leading edge LE of the full blade 9a of the compressor impeller 9. This makes it possible to directly reduce the swirling flow component of the air blocked by the movable members 210, 220 upstream of the leading edge LE of the full blade 9a.

[0088] In the first embodiment, a partition wall 302 is provided between the recessed portion 300 and the accommodation chamber AC. Providing the partition wall 302 can prevent high-temperature air flowing back through the intake passage 130 from directly flowing into the accommodation chamber AC via the recessed portion 300. This can reduce the heat transferred to the movable members 210, 220, and can prevent a decrease in the durability of the movable members 210, 220.

[0089] Second embodiment 9 is a schematic front view of an annular member 410 according to the second embodiment. Components substantially the same as those of the centrifugal compressor CC of the above embodiment are denoted by the same reference numerals and will not be described. The annular member 410 of the second embodiment differs from the annular member 310 of the first embodiment in the shapes of the partition walls 420 and the slits 440.

[0090] As shown in FIG. 9, the annular member 410 includes a plurality of partition walls 420 and an outer peripheral wall 430. The plurality of partition walls 420 are arranged at equal intervals in the circumferential direction. However, this is not limited thereto, and the plurality of partition walls 420 may be arranged at unequal intervals in the circumferential direction. The plurality of partition walls 420 extend in a direction inclined with respect to the radial direction, and divide the internal space of the recessed portion 300 in the circumferential direction. As a result, a plurality of slits 440 extending in a direction inclined with respect to the radial direction are formed between the plurality of partition walls 420. The plurality of partition walls 420 divide the plurality of slits 440 in the circumferential direction.

[0091] The partition walls 420 are inclined from the radially inner side to the radially outer side in the opposite direction to the rotation direction RD of the compressor impeller 9. In other words, the partition walls 420 are inclined from the radially outer side to the radially inner side in the rotation direction RD of the compressor impeller 9. The radially inner sides of the partition walls 420 are located further forward in the rotation direction RD than the radially outer sides. The radially outer sides of the partition walls 420 are located further rearward in the rotation direction RD than the radially inner sides. The circumferential width of the partition walls 420 is constant.

[0092] Similarly, the plurality of slits 440 are inclined from the radially inner side to the radially outer side in the opposite direction to the rotation direction RD of the compressor impeller 9. In other words, the plurality of slits 440 are inclined from the radially outer side to the radially inner side in the rotation direction RD of the compressor impeller 9. The radially inner side of the plurality of slits 440 is located forward of the rotation direction RD from the radially outer side. The radially outer side of the plurality of slits 440 is located rearward of the rotation direction RD from the radially inner side. Regarding the inclination angle of the partition wall 420, the opposite direction to the rotation direction RD of the compressor impeller 9 is set as a positive direction. At this time, the inclination angle of the plurality of partition walls 420 with respect to the radial direction is set within a range of, for example, 20° to 70°. In FIG. 9, the inclination angle of the partition wall 420 with respect to the radial direction is 60°.

[0093] The outer peripheral wall 430 connects outer diameter ends of the multiple partition walls 420. As a result, the radial outside of the multiple slits 440 is defined by the outer peripheral wall 430. In this manner, the multiple slits 440 are defined in the circumferential direction by the multiple partition walls 420, and are defined on the radial outside by the outer peripheral wall 430. The radial inside of the multiple slits 440 communicates with the intake passage 130.

[0094] FIG. 10 is a diagram for explaining the relationship between the inclination angle of the partition wall 420 and the compressor efficiency. In FIG. 10, the vertical axis represents the change in the compressor efficiency based on the absence of fins (partition walls), and the horizontal axis represents the inclination angle of the partition wall 420. Note that, regarding the inclination angle of the partition wall 420 on the horizontal axis, the direction inclined from the radially inner side to the radially outer side is the positive direction opposite to the rotation direction RD of the compressor impeller 9. As shown in FIG. 10, when the absolute value of the inclination angle of the partition wall 420 is the same, a positive inclination angle can suppress the decrease in the compressor efficiency more than a negative inclination angle. The larger the absolute value of the inclination angle of the partition wall 420, the more the decrease in the compressor efficiency can be suppressed. However, the larger the absolute value of the inclination angle of the partition wall 420, the more difficult it is to form the partition wall 420. Therefore, the maximum value of the inclination angle of the partition wall 420 is set to "70". When the inclination angle of the partition wall 420 is in the range of 20° to 70°, the pressure loss can be reduced and the decrease in compressor efficiency can be further suppressed compared to, for example, when the partition wall 420 extends in the radial direction (0°).

[0095] According to the second embodiment, it is possible to improve the compressor efficiency more than in the first embodiment.

[0096] Third embodiment 11 is a schematic front view of an annular member 510 according to the third embodiment. Components substantially the same as those of the centrifugal compressor CC of the above embodiment are denoted by the same reference numerals and will not be described. The annular member 510 of the third embodiment differs from the annular member 310 of the first embodiment and the annular member 410 of the second embodiment in the shapes of the partition walls 520 and the slits 540.

[0097] As shown in FIG. 11 , the annular member 510 includes a plurality of partition walls 520 and an outer peripheral wall 530. The plurality of partition walls 520 are arranged at equal intervals in the circumferential direction. However, without being limited thereto, the plurality of partition walls 520 may be arranged at unequal intervals in the circumferential direction. The plurality of partition walls 520 extend in a direction inclined with respect to the radial direction, and divide the internal space of the recessed portion 300 in the circumferential direction. As a result, a plurality of slits 540 extending in a direction inclined with respect to the radial direction are formed between the plurality of partition walls 520. The plurality of partition walls 520 divide the plurality of slits 540 in the circumferential direction.

[0098] The multiple partition walls 520 are inclined from the radially inner side toward the radially outer side in the rotation direction RD of the compressor impeller 9. In other words, the multiple partition walls 520 are inclined from the radially outer side toward the radially inner side in the opposite direction to the rotation direction RD of the compressor impeller 9. The radially inner sides of the multiple partition walls 520 are located rearward in the rotation direction RD than the radially outer sides. The radially outer sides of the multiple partition walls 520 are located forward in the rotation direction RD than the radially inner sides. The circumferential width of the multiple partition walls 520 is constant.

[0099] Similarly, the plurality of slits 540 are inclined from the radially inner side to the radially outer side in the rotation direction RD of the compressor impeller 9. In other words, the plurality of slits 540 are inclined from the radially outer side to the radially inner side in the opposite direction to the rotation direction RD of the compressor impeller 9. The radially inner side of the plurality of slits 540 is located on the rear side of the rotation direction RD than the radially outer side. The radially outer side of the plurality of slits 540 is located on the front side of the rotation direction RD than the radially inner side. Regarding the inclination angle of the partition wall 520, the direction of inclination from the radially inner side to the radially outer side is set to the negative direction of the rotation direction RD of the compressor impeller 9. At this time, the inclination angle of the plurality of partition walls 520 with respect to the radial direction is set within a range of, for example, -20° to -70°. In FIG. 11, the inclination angle of the partition wall 520 with respect to the radial direction is -60°.

[0100] 10, when the inclination angle of the partition wall 520 is in the range of -20° to -30°, the compressor efficiency is lower than when the partition wall 520 extends in the radial direction (0°), but the swirling component of the air can be suppressed more. As a result, the noise reduction effect can be improved compared to the first embodiment. Furthermore, when the inclination angle of the partition wall 520 is in the range of -30° to -70°, the decrease in compressor efficiency can be suppressed while maintaining the same noise reduction effect as when the inclination angle is in the range of -20° to -30°.

[0101] The outer peripheral wall 530 connects outer diameter ends of the multiple partition walls 520. As a result, the radial outside of the multiple slits 540 is defined by the outer peripheral wall 530. In this manner, the multiple slits 540 are defined in the circumferential direction by the multiple partition walls 520, and are defined on the radial outside by the outer peripheral wall 530. The radial inside of the multiple slits 540 communicates with the intake flow path 130.

[0102] According to the third embodiment, since the partition walls 520 are inclined toward the rotation direction RD of the compressor impeller 9, the air that has flowed into the slits 540 is less likely to be discharged from the slits 540 to the intake passage 130. Therefore, compared to the first embodiment in which the slits 340 extend in the radial direction and the second embodiment in which the slits 440 are inclined in the opposite direction to the rotation direction RD, the swirling flow component of the reverse flowing air can be further reduced. As a result, the noise reduction effect can be improved and the noise level can be reduced compared to the first and second embodiments.

[0103] (Fourth embodiment) 12 is a schematic front view of an annular member 610 according to the fourth embodiment. Components substantially the same as those of the centrifugal compressor CC of the above embodiment are denoted by the same reference numerals and will not be described. The annular member 610 of the fourth embodiment differs from the annular member 410 of the second embodiment in the shapes of the partition walls 620 and the slits 640.

[0104] As shown in FIG. 12, the annular member 610 includes a plurality of partition walls 620 and an outer peripheral wall 630. The plurality of partition walls 620 are arranged at equal intervals in the circumferential direction. However, without being limited thereto, the plurality of partition walls 620 may be arranged at unequal intervals in the circumferential direction. The plurality of partition walls 620 extend in a direction inclined with respect to the radial direction, and divide the internal space of the recessed portion 300 in the circumferential direction. As a result, a plurality of slits 640 extending in a direction inclined with respect to the radial direction are formed between the plurality of partition walls 620. The plurality of partition walls 620 divide the plurality of slits 640 in the circumferential direction.

[0105] The partition walls 620 are inclined from the radially inner side to the radially outer side in the opposite direction to the rotation direction RD of the compressor impeller 9. In other words, the partition walls 620 are inclined from the radially outer side to the radially inner side in the rotation direction RD of the compressor impeller 9. The radially inner sides of the partition walls 620 are located further forward in the rotation direction RD than the radially outer sides. The radially outer sides of the partition walls 620 are located further rearward in the rotation direction RD than the radially inner sides.

[0106] Moreover, the circumferential width of the multiple partition walls 620 is larger on the radially outer side than on the radially inner side. In other words, the circumferential width of the multiple partition walls 620 is smaller on the radially inner side than on the radially outer side. Specifically, the circumferential width of the multiple partition walls 620 increases toward the radially outer side. In other words, the circumferential width of the multiple partition walls 620 decreases toward the radially inner side.

[0107] Similarly, the plurality of slits 640 are inclined from the radially inner side to the radially outer side in the opposite direction to the rotation direction RD of the compressor impeller 9. In other words, the plurality of slits 640 are inclined from the radially outer side to the radially inner side in the rotation direction RD of the compressor impeller 9. The radially inner sides of the plurality of slits 640 are located forward of the rotation direction RD than the radially outer sides. The radially outer sides of the plurality of slits 640 are located rearward of the rotation direction RD than the radially inner sides. The inclination angle of the plurality of partition walls 620 with respect to the radial direction is set within a range of, for example, 20° to 70°. In FIG. 12, the inclination angle of the partition wall 620 is 60°.

[0108] The outer peripheral wall 630 connects outer diameter ends of the multiple partition walls 620. As a result, the radial outside of the multiple slits 640 is defined by the outer peripheral wall 630. In this manner, the multiple slits 640 are defined in the circumferential direction by the multiple partition walls 620, and are defined on the radial outside by the outer peripheral wall 630. The radial inside of the multiple slits 640 communicates with the intake flow path 130.

[0109] FIG. 13 is a diagram for explaining the relationship between the type of the partition wall 620 and the compressor efficiency. In FIG. 13, the case where the partition wall 320 of the first embodiment is not formed is represented by "noFin", and the case where the partition wall 320 of the first embodiment is formed is represented by "0 [deg.] Normal". In addition, the case where the partition wall 420 of the second embodiment is formed is represented by "60 [deg.] Normal", and the case where the partition wall 620 of the fourth embodiment is formed is represented by "60 [deg.] Thin". As shown in FIG. 13, the partition wall 620 of the fourth embodiment can suppress the decrease in the compressor efficiency more than the partition wall 320 of the first embodiment and the partition wall 420 of the second embodiment. This is because the circumferential width of the inner diameter end portion is smaller than that of the partition wall 320 of the first embodiment and the partition wall 420 of the second embodiment, thereby achieving a reduction in the wall friction loss of the inner diameter end portion and a reduction in the mixing loss with the main flow.

[0110] According to the fourth embodiment, the circumferential width of the inner diameter end portion of the partition wall 620 is made smaller than that of the second embodiment, so that the compressor efficiency can be improved more than that of the second embodiment.

[0111] Fifth embodiment 14 is a schematic front view of an annular member 710 according to the fifth embodiment. Components substantially the same as those of the centrifugal compressor CC of the above embodiment are denoted by the same reference numerals and will not be described. The annular member 710 of the fifth embodiment differs from the annular member 410 of the second embodiment in the shapes of the partition walls 720 and the slits 740.

[0112] As shown in FIG. 14, the annular member 710 includes a plurality of partition walls 720 and an outer peripheral wall 730. The plurality of partition walls 720 are arranged at equal intervals in the circumferential direction. However, without being limited thereto, the plurality of partition walls 720 may be arranged at unequal intervals in the circumferential direction. The plurality of partition walls 720 extend in a direction inclined with respect to the radial direction, and divide the internal space of the recessed portion 300 in the circumferential direction. As a result, a plurality of slits 740 extending in a direction inclined with respect to the radial direction are formed between the plurality of partition walls 720. The plurality of partition walls 720 divide the plurality of slits 740 in the circumferential direction.

[0113] The multiple partition walls 720 are inclined from the radially inner side to the radially outer side in the opposite direction to the rotation direction RD of the compressor impeller 9. In other words, the multiple partition walls 720 are inclined in the rotation direction RD of the compressor impeller 9 from the radially outer side to the radially inner side. The radially inner sides of the multiple partition walls 720 are located further forward in the rotation direction RD than the radially outer sides. The radially outer sides of the multiple partition walls 720 are located further rearward in the rotation direction RD than the radially inner sides.

[0114] Moreover, the circumferential width of the multiple partition walls 720 is larger on the radially inner side than on the radially outer side. In other words, the circumferential width of the multiple partition walls 720 is smaller on the radially outer side than on the radially inner side. Specifically, the circumferential width of the multiple partition walls 720 increases toward the radially inner side. In other words, the circumferential width of the multiple partition walls 720 decreases toward the radially outer side.

[0115] Similarly, the plurality of slits 740 are inclined from the radially inner side to the radially outer side in the opposite direction to the rotation direction RD of the compressor impeller 9. In other words, the plurality of slits 740 are inclined from the radially outer side to the radially inner side in the rotation direction RD of the compressor impeller 9. The radially inner sides of the plurality of slits 740 are located forward of the rotation direction RD than the radially outer sides. The radially outer sides of the plurality of slits 740 are located rearward of the rotation direction RD than the radially inner sides. The inclination angle of the plurality of partition walls 720 with respect to the radial direction is set within a range of, for example, 20° to 70°. In FIG. 14, the inclination angle of the partition walls 720 is 60°.

[0116] The outer peripheral wall 730 connects outer diameter ends of the multiple partition walls 720. As a result, the radial outside of the multiple slits 740 is defined by the outer peripheral wall 730. In this manner, the multiple slits 740 are defined in the circumferential direction by the multiple partition walls 720, and are defined on the radial outside by the outer peripheral wall 730. The radial inside of the multiple slits 740 communicates with the intake flow path 130.

[0117] In Fig. 13, the case where the partition wall 720 of the fifth embodiment is formed is represented by "60 [deg.] Thick". As shown in Fig. 13, the partition wall 720 of the fifth embodiment can suppress the decrease in compressor efficiency more than the partition wall 320 of the first embodiment, the partition wall 420 of the second embodiment, and the partition wall 620 of the fourth embodiment. This is because the circumferential width of the inner diameter end portion is larger than that of the partition wall 320 of the first embodiment, the partition wall 420 of the second embodiment, and the partition wall 620 of the fourth embodiment, thereby reducing the amount of air impinging on the partition wall 720.

[0118] According to the fifth embodiment, the compressor efficiency can be improved more than in the first, second and fourth embodiments.

[0119] Although one embodiment of the present disclosure has been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to such an embodiment. It is clear that a person skilled in the art can think of various modified or altered examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0120] In the above second to fifth embodiments, examples have been described in which the inclination angles of the partition walls 420, 520, 620, and 720 are set within a range of 20° to 70° or −20° to −70°. However, the present invention is not limited to this, and the inclination angles of the partition walls 420, 520, 620, and 720 may be outside the range of 20° to 70° or −20° to −70°. [Explanation of symbols]

[0121] AC Containment Room CC Centrifugal Compressor LE Leading Edge TC Turbocharger 9 Compressor impeller 9a Long feather 9b Short feather 100 Compressor housing (housing) 130 Intake passage 210 First movable member (movable member) 220 Second movable member (movable member) 300 Recess 310 Annular members 320 Partition Wall 330 Peripheral wall 340 Slit 410 Annular member 420 Partition Wall 430 Peripheral wall 440 Slit 510 Annular member 520 Partition Wall 530 Peripheral wall 540 Slit 610 Annular members 620 Partition Wall 630 Peripheral wall 640 Slit 710 Annular member 720 Partition Wall 730 Peripheral wall 740 Slit

Claims

1. a housing in which an intake passage is formed; A compressor impeller disposed in the intake passage and having a plurality of blades; an accommodation chamber formed in the housing on an upstream side of the blades in a flow of intake air; a movable member disposed in the accommodation chamber and movable between a protruding position protruding into the intake passage and a retracted position retracted from the intake passage; a plurality of slits formed in the housing near the blades with respect to the accommodation chamber and communicating with the intake passage; A plurality of partition walls that partition the plurality of slits in a circumferential direction; An outer circumferential wall connecting outer diameter ends of the plurality of partition walls; Equipped with The partition walls are disposed closer to the storage chamber than the leading edge of the blade. Centrifugal compressor.

2. The centrifugal compressor according to claim 1 , wherein the partition walls are inclined in a rotational direction of the compressor impeller.

3. 3. The centrifugal compressor according to claim 2, wherein an inclination angle of the plurality of partition walls is within a range of 20° to 70°, or −20° to −70° with respect to a radial direction of the compressor impeller.

4. A turbocharger comprising the centrifugal compressor according to claim 1.

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