Fuel injection nozzle unit for internal combustion engines
This patent describes a fuel injection nozzle unit for an internal combustion engine, including a nozzle body having injection holes and a pressure chamber formed therein, a nozzle needle fitted in the nozzle body and being liftable in the nozzle body to open the injection holes, a nozzle spring urging the nozzle needle in a direction of closing the injection holes, and a central plunger having one end thereof arranged opposite one end of the nozzle needle at a distance corresponding to a predetermined lift. The central plunger has another end face which is supplied with pressurized fuel, and the central plunger is liftable together with the nozzle needle against the pressure of the pressurized fuel when the predetermined lift is exceeded, the nozzle needle being lifted by a fuel pressure supplied to the pressure chamber to effect fuel injection. The improvement described here comprises: an annular-shaped, radially deformable piezo-electric element provided around the central plunger, the piezo-electric element having a substantially central hole therein which is penetrated by the central plunger; and means for selectively electrically energizing and deenergizing the piezo-electric element to selectively radially deform the piezo-electric element to thereby selectively reduce the diameter of the central hole thereof.
- Assignee:
- Diesel Kiki Co., Ltd., Tokyo
- Patent Number(s):
- US 4637553
- OSTI ID:
- 7050408
- Resource Relation:
- Patent File Date: Filed date 2 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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