Centrifugal compressor and turbocharger

A centrifugal compressor, comprising:

• an impeller;
• a compressor inlet pipe for guiding air to the impeller;
• a scroll passage disposed on an outer peripheral side of the impeller and
• a bypass passage connecting the compressor inlet pipe and the scroll passage and bypassing the impeller,
• wherein, in a cross-section perpendicular to an axis of the compressor inlet pipe, when A1 is a connection portion on a downstream side in a rotational direction of the impeller of connection portions between an inner wall surface of the compressor inlet pipe and an inner wall surface of the bypass passage, C is a virtual circle constituting the inner wall surface of the compressor inlet pipe and L1 is a tangent line of the virtual circle C at the connection portion A1, the inner wall surface of the bypass passage is formed from the connection portion A1 along the tangent line L1,
• wherein, when
• B is a virtual line connecting centers of gravity of cross-sections of the bypass passage in a flow direction of the bypass passage,
• in a cross-section perpendicular to a rotational axis of the impeller, P1 is an intersection between the virtual circle C and the virtual line B, and L2 is a tangent line of the virtual line B at the intersection P1, and
• in a meridian plane of the centrifugal compressor, P3 is an intersection between the axis O1 of the compressor inlet pipe and the tangent line L2, L5 is a line segment of the axis O1 of the compressor inlet pipe extending from the intersection P3 upstream in a flow direction of the compressor inlet pipe, and L6 is a half-line of the tangent line L2 extending from the intersection P3 into the bypass passage,
• an angle θ3 between the line segment L5 and the half-line L6 at the intersection P3 is equal to or greater than 90°.

A centrifugal compressor, comprising:

• an impeller;
• a compressor inlet pipe for guiding air to the impeller;
• a scroll passage disposed on an outer peripheral side of the impeller;
• and
• a bypass passage connecting the compressor inlet pipe and the scroll passage and bypassing the impeller,
• wherein, when
• B is a virtual line connecting centers of gravity of cross-sections of the bypass passage in a flow direction of the bypass passage,
• in a cross-section perpendicular to a rotational axis of the impeller, C is a virtual circle constituting an inner wall surface of the compressor inlet pipe, P1 is an intersection between the virtual circle C and the virtual line B, and L2 is a tangent line of the virtual line B at the intersection P1, and
• in a meridian plane of the centrifugal compressor, P3 is an intersection between the axis O1 of the compressor inlet pipe and the tangent line L2, L5 is a line segment of the axis O1 of the compressor inlet pipe extending from the intersection P3 upstream in a flow direction of the compressor inlet pipe, and L6 is a half-line of the tangent line L2 extending from the intersection P3 into the bypass passage,
• an angle θ3 between the line segment L5 and the half-line L6 at the intersection P3 satisfies 90°<θ3.

A centrifugal compressor, comprising:

• an impeller;
• a compressor inlet pipe for guiding air to the impeller;
• a scroll passage disposed on an outer peripheral side of the impeller;
• and
• a bypass passage connecting the compressor inlet pipe and the scroll passage and bypassing the impeller,
• wherein, in a cross-section perpendicular to an axis of the compressor inlet pipe, when A1 is a connection portion on a downstream side in a rotational direction of the impeller of connection portions between an inner wall surface of the compressor inlet pipe and an inner wall surface of the bypass passage, C is a virtual circle constituting the inner wall surface of the compressor inlet pipe, and L1 is a tangent line of the virtual circle C at the connection portion A1, the inner wall surface of the bypass passage is formed from the connection portion A1 along the tangent line L1,
• wherein, in a cross-section perpendicular to an axis of the compressor inlet pipe, A2 is a connection portion on an upstream side in the rotational direction of the impeller of connection portions between the virtual circle C and the inner wall surface of the bypass passage, P1 is an intersection between the virtual circle C and the virtual line B, and L2 is a tangent line of the virtual line B at the intersection P1, the axis O1 of the compressor inlet pipe is located between a straight line that passes through the connection portion A1 and is parallel to the tangent line L2 and a straight line that passes through the connection portion A2 and is parallel to the tangent line L2.