Throttle mechanism for centrifugal compressor and turbocharger

1. A centrifugal compressor comprising:

a compressor housing in which an intake passage is formed;

a compressor impeller provided in the intake passage;

an actuator that causes a rod to linearly move in a direction orthogonal with a rotation axis direction of the compressor impeller;

a connection member connected to the rod, the connection member presenting an arcuate shape;

a throttle member including a protruding portion;

a connection shaft extending in the rotation axis direction and connecting the connection member and the throttle member; and

a rotation shaft extending in a direction parallel to the connection shaft and serving as a rotation center of the throttle member,

wherein the throttle member comprises a first throttle member and a second throttle member,

wherein the connection shaft and the rotation shaft are provided to each of the first throttle member and the second throttle member, and

wherein both ends of the protruding portions of both the first throttle member and the second throttle member are in contact with each other and form an annular hole having an inner diameter smaller than that of the intake passage.

2. The centrifugal compressor according to claim 1 , wherein the throttle member is switched between a throttle position, at which the protruding portion protrudes into the intake passage, and a retracted position, at which the protruding portion is positioned on an outer side in a radial direction of the compressor impeller with respect to the throttle position, depending on a rotation angle with the rotation shaft as a rotation center.

3. The centrifugal compressor according to claim 1 , wherein the compressor housing, the connection member, the first throttle member, and the second throttle member are comprised in a four-link mechanism.

4. The centrifugal compressor according to claim 3 , wherein a rotation center of the compressor impeller is positioned in a middle of the two rotation shafts provided to the first throttle member and the second throttle member.

5. The centrifugal compressor according to claim 1 , wherein a rotation center of the compressor impeller is positioned in a middle of the two rotation shafts provided to the first throttle member and the second throttle member.

6. The centrifugal compressor according to claim 1 ,

wherein the rotation shaft connects the throttle member and a wall surface of the compressor housing facing the throttle member in the rotation axis direction, and is restricted from movement in a planar direction orthogonal to the rotation axis direction, and

the connection shaft is provided so as to be movable in the planar direction orthogonal to the rotation axis direction.

7. The centrifugal compressor according to claim 1 , wherein the connection member is provided with a rod connection portion connected to the rod at a position outer side in a radial direction of the compressor impeller with respect to the intake passage and farther from the rotation shaft than the connection shaft.

8. The centrifugal compressor according to claim 1 , wherein a tapered portion is formed in the protruding portion on a side opposite to a counterpart surface facing the compressor impeller, the tapered portion having a distance to the counterpart surface that decreases as closer to an inner side in a radial direction of the compressor impeller.

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