Centrifugal compressor

Abstract

The centrifugal compressor includes: a throttling component provided on the front side of an impeller in a housing; an actuator rod (240) connected to an actuator (250) and having a plate portion (241) formed at its front end with a plane (241a); and a connecting component (230) connected to the throttling component and having a pair of protrusions (234, 235) opposed to each other with the plate portion (241) interposed therebetween in the axial direction of the actuator rod (240).

Description

Technical Field

[0001] The present disclosure relates to a centrifugal compressor. This application claims the right of priority based on Japanese Patent Application No. 2020-87638 filed on May 19, 2020, and incorporates its content herein by reference. Background Art

[0002] A centrifugal compressor includes a compressor housing. An air inlet passage is formed in the compressor housing. A compressor impeller is disposed in the air inlet passage. If the flow rate of the air flowing into the compressor impeller decreases, the air compressed by the compressor impeller will flow back in the air inlet passage, resulting in a phenomenon called surge.

[0003] Patent Documents 1 and 2 disclose a centrifugal compressor provided with a throttling mechanism in the compressor housing. The throttling mechanism causes a throttling member to project into the air inlet passage. The throttling member throttles the air inlet passage. By throttling the air inlet passage, surge is suppressed.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: European Patent Application Publication No. 3530954 Specification

[0007] Patent Document 2: International Publication No. 2020 / 031507 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The throttling mechanisms of Patent Documents 1 and 2 include a plurality of throttling members, a connecting member, an actuator rod, and an actuator. The actuator rod is connected to the actuator. The actuator moves the actuator rod in the axial direction. The connecting member connects the actuator rod to the plurality of throttling members. When the actuator rod moves in the axial direction, the connecting member moves the plurality of throttling members between a protruding position where they project into the air inlet passage and a retracted position where they retract from the air inlet passage.

[0010] On the outer peripheral surface of the actuator rod, a recess (or a through-hole) that is recessed radially inward is formed. In the connecting member, a protrusion that is inserted into the one recess (or the through-hole) is formed. When the actuator rod moves, a force is applied to the one protrusion of the connecting member from the one recess (or the through-hole) of the actuator rod, resulting in stress concentration.

[0011] Thus, in the throttling mechanisms of Patent Documents 1 and 2, when the actuator rod moves, stress concentration occurs at the one protrusion of the connecting member. If stress concentration occurs at the one protrusion, it becomes a factor for reducing the durability of the connecting member.

[0012] An object of the present disclosure is to provide a centrifugal compressor capable of alleviating stress concentration generated in a connecting member.

[0013] Solution to the problem

[0014] To solve the above problems, a centrifugal compressor according to one aspect of the present disclosure includes: an impeller disposed in a casing; a throttle member disposed on the front side of the impeller in the casing; an actuator rod connected to an actuator and having a plate portion with a plane formed at its front end; and a connecting member connected to the throttle member and having a pair of protrusions opposed to each other with the plate portion therebetween in the axial direction of the actuator rod.

[0015] Preferably, the protruding height of the surface on the side where the pair of protrusions approach each other is smaller than the protruding height of the surface on the side where the pair of protrusions separate from each other.

[0016] Preferably, a groove portion having a U-shaped cross section in the axial direction of the actuator rod is provided between the pair of protrusions.

[0017] Preferably, the cross section of the plate portion orthogonal to the axial direction of the actuator rod is circular.

[0018] Preferably, the plate portion includes a material having a higher hardness than the portion of the actuator rod other than the plate portion.

[0019] Preferably, the actuator rod is mounted on the actuator using double nuts.

[0020] Effects of the invention are as follows.

[0021] According to the present disclosure, stress concentration generated in the connecting member can be alleviated. Description of the drawings

[0022] Figure 1 is a schematic cross-sectional view of a supercharger.

[0023] Figure 2 is Figure 1 an extracted view of the dashed portion of

[0024] Figure 3 is an exploded perspective view of the components constituting a link mechanism.

[0025] Figure 4 is Figure 2 a cross-sectional view taken along line IV-IV of

[0026] Figure 5 is a first diagram for explaining the operation of the link mechanism.

[0027] Figure 6 is a second diagram for explaining the operation of the link mechanism.

[0028] Figure 7It is the third figure for explaining the operation of the linkage mechanism.

[0029] Figure 8 It is a schematic perspective view for explaining the structure of the connecting member and the actuator rod in the comparative example.

[0030] Figure 9 It is a schematic cross-sectional view of the shaft portion of the connecting member.

[0031] Figure 10 It is a schematic perspective view for explaining the structure of the connecting member and the actuator rod in the present embodiment.

[0032] Figure 11 It is a schematic cross-sectional view of the shaft portion of the connecting member. Detailed Embodiment

[0033] Hereinafter, with reference to the drawings, one embodiment of the present disclosure will be described in detail. The dimensions, materials, other specific numerical values, etc. shown in the embodiment are merely examples for facilitating understanding, and the present disclosure is not limited without special explanation. In addition, in this specification and the drawings, elements having substantially the same function and structure are denoted by the same reference numerals, and thus repeated description is omitted. Also, illustration of elements not directly related to the present disclosure is omitted.

[0034] Figure 1 It is a schematic cross-sectional view of the supercharger TC. Regarding Figure 1 the direction of the arrow L shown as the left side of the supercharger TC. Regarding Figure 1 the direction of the arrow R shown as the right side of the supercharger TC. As Figure 1 shown, the supercharger TC includes a supercharger main body 1. The supercharger main body 1 includes a bearing housing 2, a turbine housing 3, and a compressor housing (housing) 100. The turbine housing 3 is connected to the left side of the bearing housing 2 by a fastening bolt 4. The compressor housing 100 is connected to the right side of the bearing housing 2 by a fastening bolt 5.

[0035] A receiving hole 2a is formed in the bearing housing 2. The receiving hole 2a penetrates in the left-right direction of the supercharger TC. A bearing 6 is disposed in the receiving hole 2a. Figure 1 In, as an example of the bearing 6, a full-floating bearing is shown. However, the bearing 6 may also be other radial bearings such as a semi-floating bearing or a rolling bearing. A part of a rotating shaft 7 is disposed in the receiving hole 2a. The rotating shaft 7 is supported by the bearing 6 so as to be rotatable. A turbine impeller 8 is provided at the left end portion of the rotating shaft 7. The turbine impeller 8 is rotatably received in the turbine housing 3. A compressor impeller (impeller) 9 is provided at the right end portion of the rotating shaft 7. The compressor impeller 9 is rotatably received in the compressor housing 100.

[0036] An air inlet 10 is formed in the compressor housing 100. The air inlet 10 opens on the right side of the supercharger TC. The air inlet 10 is connected to an air purifier (not shown). Air flows from the air purifier (not shown) into the air inlet 10. A diffuser passage 11 is formed between the bearing housing 2 and the compressor housing 100. The diffuser passage 11 boosts the pressure of the air. The diffuser passage 11 is formed in an annular shape from the inner side (hereinafter simply referred to as the radial direction) of the rotating shaft 7 (compressor impeller 9) toward the outer side. The inner side in the radial direction of the diffuser passage 11 communicates with the air inlet 10 via the compressor impeller 9.

[0037] A compressor scroll passage 12 is formed in the compressor housing 100. The compressor scroll passage 12 is formed in an annular shape. The compressor scroll passage 12 is formed on the outer side in the radial direction of the compressor impeller 9. The compressor scroll passage 12 is located, for example, more radially outward than the diffuser passage 11. The compressor scroll passage 12 communicates with the air inlet of an engine (not shown) and the diffuser passage 11. When the compressor impeller 9 rotates, air is sucked into the compressor housing 100 from the air inlet 10. While the sucked air flows between the blades of the compressor impeller 9, it is pressurized and accelerated. The pressurized and accelerated air is boosted in pressure in the diffuser passage 11 and the compressor scroll passage 12. The air after boosting flows out from a nozzle (not shown) and is guided to the air inlet of the engine.

[0038] An exhaust port 13, a communication passage 14, and a turbine scroll passage 15 are formed in the turbine housing 3. The exhaust port 13 opens on the left side of the supercharger TC. The exhaust port 13 is connected to an exhaust gas purification device (not shown). The communication passage 14 is located between the turbine impeller 8 and the turbine scroll passage 15. The turbine scroll passage 15 is located, for example, more radially outward than the communication passage 14.

[0039] The turbine scroll passage 15 communicates with a gas inlet (not shown). Exhaust gas discharged from the exhaust manifold of an engine (not shown) is guided to the gas inlet. The communication passage 14 enables the turbine scroll passage 15 to communicate with the exhaust port 13 via the turbine impeller 8. The exhaust gas guided from the gas inlet to the turbine scroll passage 15 is guided to the exhaust port 13 via the communication passage 14 and between the blades of the turbine impeller 8. The exhaust gas rotates the turbine impeller 8 during its flow.

[0040] The rotational force of the turbine impeller 8 is transmitted to the compressor impeller 9 via the rotating shaft 7. As described above, the air is boosted in pressure by the rotational force of the compressor impeller 9 and is guided to the air inlet of the engine.

[0041] The supercharger TC of the present embodiment includes a turbine T and a centrifugal compressor (compressor) CC. The turbine T includes a bearing housing 2, a bearing 6, a rotating shaft 7, a turbine housing 3, and a turbine impeller 8. The centrifugal compressor CC includes a bearing housing 2, a bearing 6, a rotating shaft 7, a compressor housing 100, and a compressor impeller 9. In the present embodiment, the case where the centrifugal compressor CC is driven by the turbine impeller 8 is taken as an example for description. However, it is not limited thereto. The centrifugal compressor CC may be driven by an engine (not shown) or may be driven by an electric motor (motor) (not shown). Thus, the centrifugal compressor CC of the present embodiment can be incorporated into a device other than the supercharger TC or may be a single unit.

[0042] Figure 2 is Figure 1 an extraction view of the dashed-line portion of. As Figure 2 shown, the compressor housing 100 includes a first housing member 110 and a second housing member 120. The first housing member 110 is located on the side farther from the bearing housing 2 than the second housing member 120 ( Figure 2 the right side in). The second housing member 120 is connected to the bearing housing 2. The first housing member 110 is connected to the side of the second housing member 120 opposite to the bearing housing 2 side.

[0043] The first housing member 110 is generally cylindrical in shape. A through hole 111, end faces 112, and 113 are formed in the first housing member 110. The through hole 111 extends from the end face 112 to the end face 113 along the rotation axis direction of the rotating shaft 7 (compressor impeller 9) (hereinafter, simply referred to as 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 an air inlet 10 at the end face 113.

[0044] The through hole 111 has a parallel portion 111a and a reduced-diameter portion 111b. The parallel portion 111a is located on the side closer to the end face 113 than the reduced-diameter portion 111b. The inner diameter of the parallel portion 111a is substantially constant throughout the rotation axis direction. The reduced-diameter portion 111b is located on the side 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 continuous with the parallel portion 111a is substantially equal to the inner diameter of the parallel portion 111a. The inner diameter of the reduced-diameter portion 111b becomes smaller as it is farther from the parallel portion 111a (closer to the end face 112).

[0045] The end face 112 is the end face of the first housing member 110 on the side close to (connected to) the second housing member 120. The end face 112 is a plane substantially orthogonal to the rotation center axis of the rotating shaft 7. The end face 113 is the end face of the first housing member 110 on the side far from the second housing member 120. The end face 113 is a plane substantially orthogonal to the rotation center axis of the rotating shaft 7.

[0046] A notch portion 112a and a receiving groove 112b are formed on the end face 112. The notch portion 112a is recessed from the end face 112 toward the end face 113 side. The notch portion 112a is formed at the outer peripheral portion of the end face 112. When viewed from the rotation axis direction, the notch portion 112a is, for example, substantially annular.

[0047] The receiving groove 112b is formed to be more radially inward than the notch portion 112a. The radially inner side of the receiving groove 112b communicates with the through hole 111. The receiving groove 112b is recessed from the end face 112 toward the end face 113 side. When viewed from the rotation axis direction, the receiving groove 112b is, for example, substantially annular. The receiving groove 112b has a wall surface 112c on the end face 113 side. The wall surface 112c is a plane substantially orthogonal to the rotation center axis of the rotating shaft 7.

[0048] A bearing hole 112d and a receiving hole 112e are formed in the wall surface 112c (see Figure 3 ). The bearing hole 112d extends from the wall surface 112c toward the end face 113 side along the rotation axis direction. Two bearing holes 112d are provided separately in the rotation direction (hereinafter, simply referred to as the rotation direction, circumferential direction) of the rotating shaft 7 (compressor impeller 9). The two bearing holes 112d are arranged at positions offset by 180 degrees in the rotation direction. Use Figure 3 The receiving hole 112e will be described below.

[0049] A receiving chamber AC is formed by the receiving groove 112b, the wall surface 112c, the bearing hole 112d, and the receiving hole 112e. The receiving chamber AC is formed between the first housing member 110 and the second housing member 120. The receiving chamber AC is formed on the inlet port 10 side relative to the leading edge (front edge) LE of the blades of the compressor impeller 9. The receiving chamber AC houses the following plurality of movable members (first movable member 210 and second movable member 220).

[0050] A through hole 121, an end face 122, and an end face 123 are formed in the second housing member 120. The through hole 121 extends from the end face 122 to the end face 123 along the rotation axis direction. That is, the through hole 121 penetrates the second housing member 120 in the rotation axis direction. The through hole 121 communicates with the through hole 111 of the first housing member 110.

[0051] The inner diameter of the end portion of the through hole 121 on the end face 122 side is substantially equal to the inner diameter of the end portion of the through hole 111 on the end face 112 side. A sleeve portion 121a is formed on the inner wall of the through hole 121. The sleeve portion 121a is radially opposed to the compressor impeller 9. The outer diameter of the compressor impeller 9 increases as it is farther from the leading edge LE in the rotation axis direction. The inner diameter of the sleeve portion 121a increases from the end face 122 toward the end face 123.

[0052] The end face 122 is the end face on the side of the second housing member 120 that is close to the first housing member 110. The end face 122 is a plane that is substantially orthogonal to the rotation center axis of the rotating shaft 7. The end face 123 is the end face on the side of the second housing member 120 that is far from the first housing member 110 (the side connected to the bearing housing 2). The end face 123 is a plane that is substantially orthogonal to the rotation center axis of the rotating shaft 7.

[0053] A receiving groove 122a is formed in the end face 122. The receiving groove 122a is recessed from the end face 122 toward the end face 123 side. When viewed from the rotation axis direction, the receiving groove 122a is, for example, substantially annular. The first housing member 110 is inserted into the receiving groove 122a. The receiving groove 122a has a wall surface 122b on the end face 123 side. The wall surface 122b is a plane that is substantially orthogonal to the rotation center axis of the rotating shaft 7.

[0054] The end face 112 of the first housing member 110 abuts against the wall surface 122b. At this time, the first housing member 110 is connected to the second housing member 120. A receiving chamber AC is formed between the first housing member 110 (wall surface 112c) and the second housing member 120 (wall surface 122b).

[0055] An air inlet passage 130 is formed by the through hole 111 of the first housing member 110 and the through hole 121 of the second housing member 120. That is, the air inlet passage 130 is formed in the compressor housing 100. The air inlet passage 130 communicates with the diffusion passage 11 via an air inlet 10 from an air purifier (not shown). The air purifier side (air inlet 10 side) of the air inlet passage 130 is defined as the upstream side of the intake air, and the diffusion passage 11 side of the air inlet passage 130 is defined as the downstream side of the intake air.

[0056] The compressor impeller 9 is disposed in the air inlet passage 130. The cross-sectional shape of the air inlet 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 air inlet passage 130 is not limited to this, and may be, for example, an elliptical shape.

[0057] A seal (not shown) is disposed in the notch portion 112a of the first housing member 110. The flow rate of the air flowing through the gap between the first housing member 110 and the second housing member 120 is suppressed by the seal. However, the structure of the notch portion 112a and the seal is not essential.

[0058] Return to Figure 1 , in the present embodiment, a link mechanism 200 is provided in the compressor housing 100. The link mechanism 200 is provided in the first housing member 110. However, it is not limited to this, and the link mechanism 200 may also be provided in the second housing member 120.

[0059] Figure 3 Is an exploded perspective view of the components that make up the link mechanism 200. Figure 3 Only the first housing component 110 in the compressor housing 100 is shown. As Figure 3 Shown, the link mechanism 200 includes a first movable component 210, a second movable component 220, a connecting component 230, an actuator rod 240, and an actuator 250. The link mechanism 200 is arranged on the upstream side of the air flow path 130 closer to the compressor impeller 9 in the rotational axis direction.

[0060] The first movable component 210 is arranged in the receiving groove 112b (receiving chamber AC). Specifically, the first movable component 210 is arranged between the wall surface 112c of the receiving groove 112b and the wall surface 122b of the receiving groove 122a in the rotational axis direction (refer to Figure 2 ).

[0061] The first movable component 210 has an intake upstream surface S1, an intake downstream surface S2, a radially outer surface S3, and a radially inner surface S4. The intake upstream surface S1 is the surface of the first movable component 210 on the upstream side closer to the intake. The intake downstream surface S2 is the surface of the first movable component 210 on the downstream side closer to the intake. The radially outer surface S3 is the surface of the first movable component 210 on the radially outer side. The radially inner surface S4 is the surface of the first movable component 210 on the radially inner side.

[0062] The first movable component 210 has a main body B1. The main body B1 includes a bent portion 211 and an arm portion 212. The bent portion 211 extends along the circumferential direction of the compressor impeller 9. The bent portion 211 has a substantially semi-circular arc shape. The first end face 211a and the second end face 211b in the circumferential direction of the bent portion 211 extend parallel to the radial direction and the rotational axis direction. However, the first end face 211a and the second end face 211b may also be inclined with respect to the radial direction and the rotational axis direction.

[0063] An arm portion 212 is provided on the first end face 211a side of the bent portion 211. The arm portion 212 extends radially outward from the radially outer surface S3 of the bent portion 211. And the arm portion 212 extends in a direction inclined with respect to the radial direction (towards the second movable component 220 side).

[0064] The second movable component 220 is arranged in the receiving groove 112b (receiving chamber AC). Specifically, the second movable component 220 is arranged between the wall surface 112c of the receiving groove 112b and the wall surface 122b of the receiving groove 122a in the rotational axis direction (refer to Figure 2 ).

[0065] The second movable member 220 has an intake upstream surface S5, an intake downstream surface S6, a radially outer surface S7, and a radially inner surface S8. The intake upstream surface S5 is the surface on the upstream side of the second movable member 220 closer to the intake. The intake downstream surface S6 is the surface on the downstream side of the second movable member 220 closer to the intake. The radially outer surface S7 is the surface on the radially outer side of the second movable member 220. The radially inner surface S8 is the surface on the radially inner side of the second movable member 220.

[0066] The second movable member 220 has a main body portion B2. The main body portion B2 includes a bent portion 221 and an arm portion 222. The bent portion 221 extends along the circumferential direction of the compressor impeller 9. The bent portion 221 has a substantially semi-circular arc shape. The first end face 221a and the second end face 221b in the circumferential direction of the bent portion 221 extend parallel to the radial direction and the rotational axis direction. However, the first end face 221a and the second end face 221b may also be inclined with respect to the radial direction and the rotational axis direction.

[0067] An arm portion 222 is provided on the first end face 221a side of the bent portion 221. The arm portion 222 extends radially outward from the radially outer surface S7 of the bent portion 221. Further, the arm portion 222 extends in a direction inclined with respect to the radial direction (toward the first movable member 210 side).

[0068] The bent portion 211 and the bent portion 221 face each other across the rotation center (intake flow path 130) of the compressor impeller 9. The first end face 211a of the bent portion 211 and the second end face 221b of the bent portion 221 face each other in the circumferential direction. The second end face 211b of the bent portion 211 and the first end face 221a of the bent portion 221 face each other in the circumferential direction. As will be described in detail below, the first movable member 210 and the second movable member 220 are configured such that the bent portions 211 and 221 can move radially.

[0069] The connecting member 230 connects the first movable member 210 and the second movable member 220 to the actuator rod 240. 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 substantially arc shape.

[0070] The connecting member 230 has an intake upstream surface S9, an intake downstream surface S10, a radially outer surface S11, and a radially inner surface S12. The intake upstream surface S9 is the surface on the upstream side of the connecting member 230 closer to the intake. The intake downstream surface S10 is the surface on the downstream side of the connecting member 230 closer to the intake. The radially outer surface S11 is the surface on the radially outer side of the connecting member 230. The radially inner surface S12 is the surface on the radially inner side of the connecting member 230.

[0071] The connecting member 230 has a first bearing hole 231 formed at one circumferential end side and a second bearing hole 232 formed at the other end side. The first bearing hole 231 and the second bearing hole 232 open on the intake downstream surface S10.

[0072] The first bearing hole 231 and the second bearing hole 232 are recessed from the intake downstream surface S10 in the rotational axis direction. Here, the first bearing hole 231 and the second bearing hole 232 are formed by non-through holes. However, the first bearing hole 231 and the second bearing hole 232 may also penetrate the connecting member 230 in the rotational axis direction.

[0073] The connecting member 230 forms a shaft portion 233 between the first bearing hole 231 and the second bearing hole 232. The shaft portion 233 is formed on the intake upstream surface S9 of the connecting member 230. The shaft portion 233 projects from the intake upstream surface S9 in the rotational axis direction. The cross-sectional shape of the shaft portion 233, for example, orthogonal to the central axis, is a rounded rectangle. However, it is not limited thereto, and the cross-sectional shape of the shaft portion 233, for example, orthogonal to the central axis, may also be circular, elliptical, rectangular, etc. The details of the shaft portion 233 will be described below.

[0074] Figure 4 is Figure 2 a cross-sectional view taken along line IV-IV. As Figure 4 shown by the dashed line in, the first movable member 210 has a connecting shaft portion 213 and a rotational shaft portion 214. The connecting shaft portion 213 and the rotational shaft portion 214 project from the intake upstream surface S1 (refer to Figure 2 ) of the arm portion 212 of the first movable member 210 that faces the wall surface 112c in the rotational axis direction. Figure 4 In, the connecting shaft portion 213 and the rotational shaft portion 214 extend toward the inside of the paper surface. The rotational shaft portion 214 extends substantially parallel to the connecting shaft portion 213. The connecting shaft portion 213 and the rotational shaft portion 214 are cylindrical in shape.

[0075] 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 through the first bearing hole 231. The connecting shaft portion 213 is rotatably shaft-supported in the first bearing hole 231. The outer diameter of the rotational shaft portion 214 is smaller than the inner diameter of the bearing hole 112d of the first housing member 110. The rotational shaft portion 214 is inserted through the upper vertical bearing hole 112d of the two bearing holes 112d. The rotational shaft portion 214 is rotatably shaft-supported in the bearing hole 112d.

[0076] The second movable member 220 has a connecting shaft portion 223 and a rotational shaft portion 224. The connecting shaft portion 223 and the rotational shaft portion 224 project from the intake upstream surface S5 (refer to Figure 2)Protrusion. Figure 4 Among them, the connecting shaft portion 223 and the rotating shaft portion 224 extend toward the inside of the paper surface. The rotating shaft portion 224 extends substantially parallel to the connecting shaft portion 223. The connecting shaft portion 223 and the rotating shaft portion 224 are cylindrical in shape.

[0077] 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 through the second bearing hole 232. The connecting shaft portion 223 is rotatably supported by 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 through the lower bearing hole 112d among the two bearing holes 112d in the vertical direction. The rotating shaft portion 224 is rotatably supported by the bearing hole 112d.

[0078] Return to Figure 3 , the actuator rod 240 is substantially cylindrical in shape. The actuator rod 240 is formed with a plate portion 241 at one end and a fastening portion 243 at the other end. The plate portion 241 is formed in a plate shape. The end face of the plate portion 241 on the side opposite to the fastening portion 243 has a plane 241a orthogonal to the central axis of the actuator rod 240. That is, the front end of the actuator rod 240 has a plane 241a orthogonal to the central axis of the actuator rod 240.

[0079] In the present embodiment, the cross-section of the plate portion 241 orthogonal to the central axis direction of the actuator rod 240 is circular. However, it is not limited thereto, and the cross-section of the plate portion 241 may also be rectangular, elliptical, or polygonal.

[0080] The fastening portion 243 is fastened to the actuator 250. For example, an external thread 243a is formed on the fastening portion 243. For example, an internal thread 250a is formed on the actuator 250. The actuator rod 240 is attached to the actuator 250 by screwing the external thread 243a of the fastening portion 243 with the internal thread 250a of the actuator 250. The actuator 250 to which the actuator rod 240 is attached is provided, for example, on the compressor housing 100.

[0081] The actuator 250 is, for example, a linear actuator. However, as long as the actuator 250 can drive the actuator rod 240 in the axial direction, it may be composed of, for example, a motor, a hydraulic cylinder, etc.

[0082] An insertion hole 114 is formed in the first housing member 110. One end 114a of the insertion hole 114 opens outside the first housing member 110. The insertion hole 114 extends, for example, in the vertical direction. The insertion hole 114 is located more radially outside than the through hole 111 (inflow passage 130). The plate portion 241 side of the actuator rod 240 is inserted through the insertion hole 114.

[0083] The accommodation hole 112e is recessed from the wall surface 112c toward the intake port 10. The accommodation hole 112e is located on the side (the second housing member 120 side) farther from the intake port 10 than the insertion through-hole 114. When viewed from the rotation axis direction, the accommodation hole 112e is substantially arc-shaped. The accommodation hole 112e extends longer in the circumferential direction than the connecting member 230. The accommodation hole 112e is separated from the bearing hole 112d in the circumferential direction.

[0084] A communication hole 115 is formed in the accommodation hole 112e. The communication hole 115 communicates the insertion through-hole 114 with the accommodation hole 112e. The communication hole 115 is formed in a substantially central portion in the circumferential direction in the accommodation hole 112e. The communication hole 115 is, for example, a long hole extending substantially parallel to the extending direction of the insertion through-hole 114. The width in the long side direction of the communication hole 115 is larger than the width in the short side direction.

[0085] The connecting member 230 is accommodated in the accommodation hole 112e. The circumferential length of the accommodation hole 112e is longer than the circumferential length of the connecting member 230, and the radial width is larger than the radial width of the connecting member 230. Therefore, the connecting member 230 is allowed to move in the plane direction perpendicular to the rotation axis direction inside the accommodation hole 112e.

[0086] The shaft portion 233 is inserted through the communication hole 115 into the insertion through-hole 114. A plate portion 241 of the actuator rod 240 is inserted through the insertion through-hole 114. The plate portion 241 faces the communication hole 115 in the rotation axis direction of the compressor impeller 9. The shaft portion 233 engages with the plate portion 241. Use Figure 10 The engagement between the shaft portion 233 and the plate portion 241 will be described below. By engaging the shaft portion 233 with the plate portion 241, the connecting member 230 is driven in conjunction with the actuator rod 240. And, the first movable member 210 and the second movable member 220 are driven in conjunction with the connecting member 230.

[0087] The first movable member 210 and the second movable member 220 are accommodated in the accommodation groove 112b. That is, the first movable member 210 and the second movable member 220 are provided on the front side (upstream side) of the compressor impeller 9. Thus, the first movable member 210, the second movable member 220, and the connecting member 230 are accommodated in the accommodation chamber AC formed between the first housing member 110 and the second housing member 120.

[0088] As described above, the link mechanism 200 includes a first movable member 210, a second movable member 220, and a connecting member 230. The first movable member 210, the second movable member 220, the first housing member 110, and the connecting member 230 have four links (joints). A four-link mechanism is formed by the first movable member 210, the second movable member 220, the first housing member 110, and the connecting member 230. The degree of freedom of the four-link mechanism is 1, and the driven link is restricted to one type of motion (defined interlock). By using the four-link mechanism, the control of the link mechanism 200 becomes easy.

[0089] Figure 5 It is the first diagram for explaining the operation of the link mechanism 200. In the following Figure 5 , Figure 6 , Figure 7 , diagrams of the link mechanism 200 as viewed from the intake port 10 side are shown.

[0090] In Figure 5 the configuration shown, the first movable member 210 and the second movable member 220 are in contact with each other. At this time, as shown in Figure 2 and Figure 4 , the protrusion 215 at the radially inner part of the first movable member 210 protrudes (is exposed) into the intake air flow path 130. The protrusion 225 at the radially inner part of the second movable member 220 protrudes (is exposed) into the intake air flow path 130. The positions of the first movable member 210 and the second movable member 220 in this state are referred to as the protruding positions (or throttling positions).

[0091] As shown in Figure 5 , at the protruding position, the circumferential ends 215a, 215b of the protrusion 215 are in contact with the circumferential ends 225a, 225b of the protrusion 225. An annular hole 260 is formed by the protrusion 215 and the protrusion 225. The inner diameter of the annular hole 260 is smaller than the inner diameter of the part of the intake air flow path 130 where the protrusions 215 and 225 protrude. The inner diameter of the annular hole 260 is, for example, smaller than the inner diameter of any part of the intake air flow path 130.

[0092] Figure 6 It is the second diagram for explaining the operation of the link mechanism 200. Figure 7 It is the third diagram for explaining the operation of the link mechanism 200. The actuator 250 moves the actuator rod 240 linearly in a direction crossing the rotation axis direction of the compressor impeller 9 (the up-down direction in Figure 6 , Figure 7 ). The actuator 250 drives the actuator rod 240 in the central axis direction of the actuator rod 240. Figure 6 and Figure 7 , the actuator rod 240 is from Figure 5The shown position moves upward. Compared with Figure 6 's configuration, in Figure 7 's configuration, the actuator rod 240 has a larger movement amount relative to Figure 5 's configuration.

[0093] If the actuator rod 240 moves upward in Figure 6 and Figure 7 , the connecting member 230 moves upward via the shaft portion 233 in Figure 6 and Figure 7 . At this time, the connecting member 230 is slightly allowed to rotate about the central axis of the shaft portion 233. And, a gap is provided between the connecting member 230 and the receiving hole 112e in a plane perpendicular to the rotation axis direction of the compressor impeller 9. Therefore, the connecting member 230 is slightly allowed to move in the plane direction perpendicular to the rotation axis direction.

[0094] 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 show a behavior with one degree of freedom relative to the first housing member 110. Specifically, within the above-mentioned allowable range, the connecting member 230 slightly swings in the left-right direction while slightly rotating counterclockwise in Figure 6 and Figure 7 .

[0095] The rotating shaft portion 214 in the first movable member 210 is pivotally supported by the first housing member 110. The movement of the rotating shaft portion 214 in the plane direction perpendicular to the rotation axis direction is restricted. The connecting shaft portion 213 is pivotally supported by the connecting member 230. Since the movement of the connecting member 230 is allowed, the connecting shaft portion 213 is configured to be able to move in the plane direction perpendicular to the rotation axis direction. As a result, as the connecting member 230 moves, the first movable member 210 rotates clockwise in Figure 6 and Figure 7 with the rotating shaft portion 214 as the rotation center.

[0096] Similarly, the rotating shaft portion 224 in the second movable member 220 is pivotally supported by the first housing member 110. The movement of the rotating shaft portion 224 in the plane direction perpendicular to the rotation axis direction is restricted. The connecting shaft portion 223 is pivotally supported by the connecting member 230. Since the movement of the connecting member 230 is allowed, the connecting shaft portion 223 is configured to be able to move in the plane direction perpendicular to the rotation axis direction. As a result, as the connecting member 230 moves, the second movable member 220 rotates clockwise in Figure 6 and Figure 7 with the rotating shaft portion 224 as the rotation center.

[0097] In this way, the first movable member 210 and the second movable member 220 move according toFigure 6 , Figure 7 , the protruding portions 215 and 225 move in a direction away from each other. The protruding portions 215 and 225 move to a position radially outside the protruding position (retracted position). In the retracted position, for example, the protruding portions 215 and 225 are coplanar with the inner wall surface of the intake air flow path 130, or are located radially outside the inner wall surface of the intake air flow path 130. When moving from the retracted position to the protruding position, in the order of Figure 7 , Figure 6 , Figure 5 , the first movable member 210 and the second movable member 220 approach and abut against each other. In this way, the first movable member 210 and the second movable member 220 are switched between the protruding position and the retracted position according to the rotation angle around the rotation shaft portions 214 and 224.

[0098] In this way, 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 air flow path 130 and a retracted position where they do not protrude (protrude) into the intake air flow path 130. In the present embodiment, the first movable member 210 and the second movable member 220 move in the radial direction of the compressor impeller 9. However, it is not limited thereto, and the first movable member 210 and the second movable member 220 may also rotate around the rotation axis (circumferential direction) of the compressor impeller 9 and move between the protruding position and the retracted position. For example, the first movable member 210 and the second movable member 220 may be baffle blades having two or more blades.

[0099] When the first movable member 210 and the second movable member 220 are in the retracted position (hereinafter, also referred to as the retracted position state), they do not protrude into the intake air flow path 130. Therefore, the pressure loss of the intake air (air) flowing through the intake air flow path 130 becomes smaller.

[0100] And, as Figure 2 shown, when the first movable member 210 and the second movable member 220 are in the protruding position (hereinafter, also referred to as the protruding position state), the protruding portions 215 and 225 protrude into the intake air flow path 130. At this time, the protruding portions 215 and 225 are disposed in the intake air flow path 130. When the protruding portions 215 and 225 protrude into the intake air flow path 130, the flow path cross-sectional area of the intake air flow path 130 becomes smaller.

[0101] Here, as the flow rate of the air flowing into the compressor impeller 9 decreases, sometimes the air compressed by the compressor impeller 9 may flow back in the intake air flow path 130 (that is, the air flows from the downstream side toward the upstream side). That is, as the flow rate of the air flowing into the compressor impeller 9 decreases, sometimes a flow-back phenomenon called surge may occur.

[0102] In Figure 2In the protruding position state shown, the protrusions 215 and 225 are located more radially inward than the outermost diameter end of the leading edge LE of the compressor impeller 9. Thus, the air flowing back in the intake air flow path 130 is blocked by the protrusions 215 and 225. Therefore, the first movable member 210 and the second movable member 220 in the protruding position state can suppress the backflow of air in the intake air flow path 130.

[0103] Moreover, as the flow path cross-sectional area of the intake air flow path 130 becomes smaller, the flow velocity of the air flowing into the compressor impeller 9 increases. Thereby, the incident angle with respect to the blades of the compressor impeller 9 decreases, and the air flow can be stabilized. As a result, surge in the centrifugal compressor CC can be suppressed. That is, the centrifugal compressor CC of the present embodiment can expand the operating region of the centrifugal compressor CC to the low flow rate side by protruding the protrusions 215 and 225 into the intake air flow path 130.

[0104] In this way, the first movable member 210 and the second movable member 220 are configured as throttle members that throttle the intake air flow path 130. That is, in the present embodiment, the link mechanism 200 is configured as a throttle mechanism that throttles the intake air 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 air flow path 130 by driving the link mechanism 200.

[0105] Next, the engagement relationship between the connecting member 230 and the actuator rod 240 in the link mechanism 200 will be described in detail. First, the engagement relationship between the connecting member 330 and the actuator rod 340 in the link mechanism 300 of the comparative example will be described. After that, the engagement relationship between the connecting member 230 and the actuator rod 240 in the link mechanism 200 of the present embodiment will be described.

[0106] Figure 8 is a schematic perspective view for explaining the structures of the connecting member 330 and the actuator rod 340 in the comparative example. The same reference numerals are given to the components that are substantially the same as those of the supercharger TC in the above-described embodiment, and the description thereof is omitted. The shapes of the connecting member 330 and the actuator rod 340 of the link mechanism 300 of the comparative example are different from the shapes of the connecting member 230 and the actuator rod 240 in the above-described embodiment. The structure of the supercharger TC other than this is the same as that of the supercharger TC in the above-described embodiment.

[0107] As Figure 8As shown, the connecting member 330 of the comparative example has a first bearing hole 231, a second bearing hole 232, and a shaft portion 333. Only the shape of the shaft portion 333 of the connecting member 330 of the comparative example is different from that of the shaft portion 233 of the connecting member 230 of the above-described embodiment. The shaft portion 333 has a substantially cylindrical shape. In addition, the length of the shaft portion 333 of the comparative example in the central axis direction is equal to the length of the shaft portion 233 of the above-described embodiment in the central axis direction.

[0108] The actuator rod 340 of the comparative example has a through hole 341 and a fastening portion 343. The through hole 341 penetrates the actuator rod 340 in the radial direction. The shape of the cross section of the through hole 341 orthogonal to the central axis is substantially circular. The fastening portion 343 is fastened to the actuator 250. External threads 343a are formed, for example, on the fastening portion 343. Internal threads 250a are formed, for example, on the actuator 250. The actuator rod 340 is attached to the actuator 250 by screwing the external threads 343a of the fastening portion 343 with the internal threads 250a of the actuator 250.

[0109] As Figure 8 shown, the shaft portion 333 of the connecting member 330 is inserted through the through hole 341 of the actuator rod 340. Therefore, if the actuator 250 drives the actuator rod 340, the connecting member 330 moves in the central axis direction of the actuator rod 340 as the actuator rod 340 moves in the central axis direction. At this time, a pressing force is applied to the shaft portion 333 of the connecting member 330 from the through hole 341 of the actuator rod 340.

[0110] Figure 9 is a schematic cross-sectional view of the shaft portion 333 of the connecting member 330. Figure 9 In [it], D1 is the first direction in which the actuator rod 340 presses the shaft portion 333. Figure 9 In [it], D2 is the second direction in which the actuator rod 340 presses the shaft portion 333. The first direction D1 and the second direction D2 are the central axis direction of the actuator rod 340. The first direction D1 is the direction opposite to the second direction D2.

[0111] As Figure 9 shown, if the shaft portion 333 is pressed by the actuator rod 340 in the first direction D1, the shaft portion 333 is slightly deformed in the first direction D1. And, if the shaft portion 333 is pressed by the actuator rod 340 in the second direction D2, the shaft portion 333 is slightly deformed in the second direction D2.

[0112] At this time, Figure 9In [reference], stress concentration occurs at the boundary portions R1 and R2 between the intake upstream surface S9 of the connecting member 330 indicated by the double-dashed line and the shaft portion 333. That is, stress concentration occurs at two portions (boundary portions R1 and R2) on the first direction D1 side and the second direction D2 side of the shaft portion 333. If stress concentration occurs at the boundary portions R1 and R2, it becomes a factor for reducing the durability of the connecting member 330.

[0113] In addition, as described in Figure 8 , the actuator rod 340 is attached to the actuator 250 by threadedly engaging the external thread 343a with the internal thread 250a. However, if the actuator rod 340 rotates, the central axis of the through hole 341 deviates from the central axis of the shaft portion 333. When the central axis of the through hole 341 and the central axis of the shaft portion 333 are not substantially aligned, the shaft portion 333 cannot be inserted through the through hole 341. Therefore, the operator needs to assemble the actuator rod 340 to the actuator 250 such that the central axis of the through hole 341 and the central axis of the shaft portion 333 are substantially aligned. As a result, there is a problem that the assembly operation of the link mechanism 300 becomes complicated.

[0114] Figure 10 is a simplified perspective view for explaining the structures of the connecting member 230 and the actuator rod 240 in the present embodiment. As Figure 10 shown, the connecting member 230 of the present embodiment has a shaft portion 233 different from the shaft portion 333 of the comparative example. And the actuator rod 240 of the present embodiment has a different shape (plate portion 241) from the actuator rod 340 of the comparative example.

[0115] The shaft portion 233 includes a pair of protrusion portions 234 and 235. The pair of protrusion portions 234 and 235 are disposed opposite to each other with the plate portion 241 therebetween in the central axis direction of the actuator rod 240. A groove portion 236 is formed between the pair of protrusion portions 234 and 235.

[0116] The actuator rod 240 of the present embodiment has a plate portion 241 and a fastening portion 243. In the actuator rod 240 of the present embodiment, the through hole 341 of the comparative example is not formed, and the plate portion 241 is provided instead of the through hole 341. The plate portion 241 has a flat surface 241a at the front end. On the other hand, the side of the plate portion 241 opposite to the flat surface 241a is connected to the shaft portion 240a of the actuator rod 240. The plate portion 241 is disposed between the pair of protrusion portions 234 and 235 and engages with the groove portion 236.

[0117] The plate portion 241 is made of a material having a hardness higher than that of the portions of the actuator rod 240 other than the plate portion 241. For example, in the actuator rod 240 of the present embodiment, only the plate portion 241 is subjected to electroless plating treatment. However, it is not limited thereto, and the plate portion 241 may be constituted by a component independent of the actuator rod 240 and attached to the actuator rod 240. In this case, the plate portion 241 is made of a material having a hardness higher than that of the actuator rod 240. Thereby, the wear resistance of the plate portion 241 can be improved as compared with the case where the plate portion 241 is made of the same material as the actuator rod 240.

[0118] External threads 243a are formed on the fastening portion 243, and internal threads 250a are formed on the actuator 250. The actuator rod 240 is attached to the actuator 250 by threadedly engaging the external threads 243a of the fastening portion 243 with the internal threads 250a of the actuator 250. Here, a nut 245 is threadedly engaged with the external threads 243a. Internal threads (not shown) are formed on the nut 245, and the internal threads (not shown) are engaged with the external threads 243a. The nut 245 rotates around the central axis of the actuator rod 240, and thus can move in the direction of the central axis of the actuator rod 240 within the range where the external threads 243a are formed. If the nut 245 moves toward the actuator 250 side, the nut 245 contacts the actuator 250. If the nut 245 is fastened to the actuator 250 side in this state, the movement of the actuator rod 240 relative to the actuator 250 is restricted. In this way, the actuator rod 240 is attached to the actuator 250 by using a so-called double nut. Thereby, the length from the actuator 250 to the front end (plate portion 241) of the actuator rod 240 can be easily adjusted.

[0119] As Figure 10 shown, the plate portion 241 of the connecting member 230 is inserted into the groove portion 236 of the shaft portion 233. Therefore, if the actuator 250 drives the actuator rod 240, the connecting member 230 moves in the direction of the central axis of the actuator rod 240 as the actuator rod 240 moves in the direction of the central axis. At this time, a pressing force is applied to the shaft portion 233 of the connecting member 230 from the plate portion 241 of the actuator rod 240.

[0120] Figure 11 is a schematic cross-sectional view of the shaft portion 233 of the connecting member 230. Figure 11 The cross section including the central axis of the shaft portion 233 is shown. Figure 11 In, D1 is the first direction in which the actuator rod 240 presses the shaft portion 233. Figure 11 In, D2 is the second direction in which the actuator rod 240 presses the shaft portion 233. The first direction D1 and the second direction D2 are the directions of the central axis of the actuator rod 240. The first direction D1 is the direction opposite to the second direction D2.

[0121] AsFigure 11 As shown, the cross-section of the groove portion 236 along the direction in which the pair of protrusion portions 234 and 235 are arranged (the axial direction of the actuator rod 240) is U-shaped. Moreover, the protruding height of the surfaces of the pair of protrusion portions 234 and 235 on the side where they approach each other is lower than the protruding height of the surfaces of the pair of protrusion portions 234 and 235 on the side where they are separated from each other. Specifically, the distance from the front ends 234a and 235a of the pair of protrusion portions 234 and 235 to the bottom surface of the groove portion 236 is shorter than the distance from the front ends 234a and 235a of the pair of protrusion portions 234 and 235 to the intake upstream surface S9. That is, the groove portion 236 formed between the pair of protrusion portions 234 and 235 is located closer to the actuator rod 240 side than the intake upstream surface S9 of the connecting member 230. In other words, the distance from the front ends 234a and 235a of the pair of protrusion portions 234 and 235 to the bottom surface of the groove portion 236 (i.e., the depth of the groove portion 236) is shorter than the distance from the front ends 234a and 235a to the base end portions of the pair of protrusion portions 234 and 235.

[0122] When the shaft portion 233 is pressed by the actuator rod 240 in the first direction D1, the protrusion portion 234 on the side closer to the first direction D1 among the pair of protrusion portions 234 and 235 is deformed slightly in the first direction D1 as shown by the dashed line in Figure 11 . At this time, Figure 11 , stress concentration occurs at the boundary portion R3 between the protrusion portion 234 shown by the double-dot chain line and the bottom surface of the groove portion 236. On the other hand, the side surface portion R4 on the side of the protrusion portion 234 opposite to the boundary portion R3 is not the boundary portion between the protrusion portion 234 and the intake upstream surface S9 of the connecting member 230, but is substantially flat. Therefore, compared with the boundary portion R3, almost no stress concentration occurs on the side surface portion R4.

[0123] Moreover, when the shaft portion 233 is pressed by the actuator rod 240 in the second direction D2, the protrusion portion 235 on the side closer to the second direction D2 among the pair of protrusion portions 234 and 235 is deformed slightly in the second direction D2 as shown by the single-dot chain line in Figure 11 . At this time, Figure 11 , stress concentration occurs at the boundary portion R5 between the protrusion portion 235 shown by the double-dot chain line and the bottom surface of the groove portion 236. On the other hand, the side surface portion R6 on the side of the protrusion portion 235 opposite to the boundary portion R5 is not the boundary portion between the protrusion portion 235 and the intake upstream surface S9 of the connecting member 230, but is substantially flat. Therefore, compared with the boundary portion R5, almost no stress concentration occurs on the side surface portion R6.

[0124] Thus, when the shaft portion 233 is pressed by the actuator rod 240 in the first direction D1, no stress is applied to the protrusion portion 235, so that no stress concentration occurs at the boundary portion R5. On the other hand, when the shaft portion 233 is pressed by the actuator rod 240 in the second direction D2, no stress is applied to the protrusion portion 234, so that no stress concentration occurs at the boundary portion R3. In addition, the bottom surface of the groove portion 236 is formed in a U shape, and it is difficult for stress concentration to occur at the boundary portions R3 and R5.

[0125] Therefore, according to the present embodiment, it is possible to make the stress concentration at the shaft portion 233 (boundary portion R3 or boundary portion R5) smaller than the stress concentration at the shaft portion 333 (boundary portion R1 or boundary portion R2) of the comparative example.

[0126] In addition, as Figure 10 shown, the plate portion 241 is located at the front end of the shaft portion 240a of the actuator rod 240. When the actuator rod 240 presses the shaft portion 233, stress concentration occurs at the boundary portion between the plate portion 241 and the shaft portion 240a. However, almost no stress concentration occurs on the plane 241a of the plate portion 241. Here, when the plate portion 241 is located in the middle of the shaft portion 240a of the actuator rod 240, the plate portion 241 forms two boundary portions with the shaft portion 240a on both sides in the central axis direction of the actuator rod 240. In this case, if the actuator rod 240 presses the shaft portion 233, stress concentration occurs at the two boundary portions. Therefore, when the plate portion 241 is located at the front end of the shaft portion 240a of the actuator rod 240, compared with the case where it is located in the middle of the shaft portion 240a, the stress concentration generated in the plate portion 241 can be reduced.

[0127] Moreover, in the present embodiment, the distances from the front ends 234a and 235a of the pair of protrusion portions 234 and 235 to the boundary portions R3 and R5 are shorter than the distances from the front end 333a of the shaft portion 333 of the comparative example to the boundary portions R1 and R2. Therefore, compared with the stress concentration points (boundary portions R1 and R2) generated in the shaft portion 333, the stress concentration points (boundary portions R3 and R5) generated in the pair of protrusion portions 234 and 235 can be made closer to the pressing point pressed by the actuator rod 240. As a result, the stress concentration at the protrusion portions 234 and 235 can be made smaller than the stress concentration at the shaft portion 333 of the comparative example.

[0128] As described above, the link mechanism 200 of the present embodiment includes: an actuator rod 240 having a plate portion 241; and a connecting member 230 having a pair of protrusion portions 234 and 235. The plate portion 241 is disposed between the pair of protrusion portions 234 and 235. Thereby, the stress concentration generated at the boundary portions R3 and R5 of the pair of protrusion portions 234 and 235 can be alleviated. As a result, a decrease in the durability of the connecting member 230 can be suppressed.

[0129] Moreover, as inFigure 10 As described, the actuator rod 240 is mounted to the actuator 250 by being threadedly engaged with the internal thread 250a via the external thread 243a. However, since the plate portion 241 is formed in a substantially cylindrical shape, it can be engaged with the groove portion 236 of the shaft portion 233 at any phase around the central axis of the actuator rod 240. Therefore, the operator can engage the plate portion 241 with the groove portion 236 without considering the rotational phase of the actuator rod 240. As a result, the assembly operation of the link mechanism 200 can be simplified.

[0130] As described above, one embodiment of the present disclosure has been described with reference to the accompanying drawings. Of course, the present disclosure is not limited to such an embodiment. Those skilled in the art can obviously conceive various modification examples or correction examples within the scope described in the claims, and these modification examples or correction examples also belong to the technical scope of the present disclosure.

[0131] In the above embodiment, an example in which the distance from the front ends 234a, 235a of the pair of protrusions 234, 235 to the bottom surface of the groove portion 236 is shorter than the distance from the front ends 234a, 235a of the pair of protrusions 234, 235 to the intake upstream surface S9 has been described. However, it is not limited thereto, and the distance from the front ends 234a, 235a of the pair of protrusions 234, 235 to the bottom surface of the groove portion 236 may also be equal to the distance from the front ends 234a, 235a of the pair of protrusions 234, 235 to the intake upstream surface S9.

[0132] In the above embodiment, an example in which the bottom surface of the groove portion 236 has a U-shaped configuration has been described. However, it is not limited thereto, and the bottom surface of the groove portion 236 may also have an arc shape or a rectangular shape.

[0133] In the above embodiment, an example in which the plate portion 241 is substantially cylindrical has been described. However, it is not limited thereto, and the plate portion 241 may, for example, also have a rectangular parallelepiped shape or a polygonal prism shape.

[0134] In the above embodiment, an example in which the plate portion 241 includes a material having a higher hardness than the portions of the actuator rod 240 other than the plate portion 241 has been described. However, it is not limited thereto, and the plate portion 241 may also be made of the same material as the actuator rod 240.

[0135] In the above embodiment, an example in which a nut 245 is provided on the actuator rod 240 has been described. However, it is not limited thereto, and the nut 245 may not be provided on the actuator rod 240.

[0136] Description of reference numerals

[0137] CC - Centrifugal compressor, R3 - Boundary part, R5 - Boundary part, S9 - Intake upstream surface, TC - Supercharger, 100 - Compressor housing, 110 - First housing component, 120 - Second housing component, 200 - Linkage mechanism, 210 - First movable part, 215 - Protrusion, 220 - Second movable part, 225 - Protrusion, 230 - Connecting component, 231 - First bearing hole, 232 - Second bearing hole, 233 - Shaft part, 234 - Protrusion, 234a - Front end, 235 - Protrusion, 235a - Front end, 236 - Groove part, 240 - Actuator rod, 241 - Plate part, 241a - Plane, 243 - Fastening part, 243a - External thread, 245 - Nut, 250 - Actuator, 250a - Internal thread.

Claims

1. A centrifugal compressor, characterized in that, Comprising: An impeller, which is arranged inside a housing; A throttling component, which is arranged on the front side of the impeller in the above-mentioned housing; An actuator rod, which is connected to an actuator and has a plate portion with a flat surface formed at its front end; and A connecting component, which is connected to the above-mentioned throttling component and has a pair of protrusions that are opposed to each other across the above-mentioned plate portion in the axial direction of the above-mentioned actuator rod, The above-mentioned plate portion comprises a material with a hardness higher than that of the part of the above-mentioned actuator rod other than the above-mentioned plate portion, The cross-section of the above-mentioned plate portion orthogonal to the axial direction of the above-mentioned actuator rod is circular, and the above-mentioned plate portion engages with a groove portion formed between the above-mentioned pair of protrusions.

2. The centrifugal compressor according to claim 1, wherein The protruding height of the surface on the side where the above-mentioned pair of protrusions approach each other is smaller than the protruding height of the surface on the side where the above-mentioned pair of protrusions separate from each other.

3. The centrifugal compressor according to claim 1 or 2, wherein The cross-section of the above-mentioned groove portion along the axial direction of the above-mentioned actuator rod is U-shaped.

4. The centrifugal compressor according to claim 1 or 2, wherein The above-mentioned actuator rod is mounted on the above-mentioned actuator by means of double nuts.

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