Patent ID: 7178360

Claim:
An ejector comprising: a high pressure space into which high pressure fluid flows from an inlet; a throttle means having a throttle portion by which a passage area of the high pressure fluid is reduced from the high pressure space toward a throat portion; a needle valve for changing a degree of opening of the throttle means when the needle valve is displaced in the axial direction (R) of the throttle portion; a tapered portion formed at an end portion on the throat portion side of the needle valve; and a suction space having a second inlet into which fluid flows, the throttle means being arranged in the suction space, the fluid being sucked from the second inlet into the suction space by an entraining action of the hydraulic fluid jetting out from the throat portion at high speed, wherein a plurality of the tapered portions are provided and the taper angles (θ 1 , θ 2 ) of the plurality of the tapered portions are different from each other.