| 摘要 |
<p>An injection nozzle (20) for an internal combustion engine comprises a nozzle body (22) provided with a bore (24) within which a valve needle (23) is movable along a primary valve needle axis (A-A), the valve needle (23) being engageable with a valve seating (25) defined by the bore (24) to control fuel delivery through a nozzle outlet, and including a first region (36), a second region (38) and a seating region (33) defined by a transition between the first and second regions (36, 38) which seats against the valve seating (25) when the injection nozzle (20) is in a non-injecting state. A relieved region (40) is disposed upstream of the seating region (33), the relieved region (40) and one of the valve seating (25) and the first region (36) defining an anti-cavitation volume (50) therebetween when the injection nozzle (20) is in the non-injecting state. The valve needle (23) and the valve seating (25) together define a restriction (47) upstream of the relieved region (40) for restricting the flow of fuel into and out of the anti-cavitation volume (50) when the injection nozzle (20) is in the non-injecting state in order to reduce pressure wave activity upstream of the seating region (33).</p> |
