| 摘要 |
An axi-symmetric injection nozzle has an inner body with a tapered bore, an adjustment screw, and an outer tube. A seat lip is machined on the outside perimeter of the outer extremity of the inner body. A head lip is machined on the outer perimeter of the adjustment screw head which engages the tapered bore in the outer extremity of the inner body. When the adjustment screw is tightened the head lip swages the seat lip radially outward, contacting the inner surface of the outer tube to form a fluid seal between inner body and outer tube. Further flexural deflection of the thin cylindrical section of inner body containing seat lip in a radially outward direction by tightening adjustment screw not only closes the annular passage between the inner body and the outer tube but wedges the seat lip against the outer tube forcefully to elastically deflect the outer tube radially and establish a pre-load tensile stress in the outer extremity of outer tube. A given tensile pre-load in the outer tube will establish, from a number of turns tightening the screw, the fluid pressure level that must be attained in the annular passage before that fluid pressure will generate sufficient hoop tension in the outer tube to expand it outwardly away from the seat lip permitting fluid to flow from the nozzle.
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