Fluid sprinkling – spraying – and diffusing – With means to vibrate or jiggle discharge – By electric transducer
Reexamination Certificate
2000-12-15
2001-11-13
Ganey, Steven J. (Department: 3752)
Fluid sprinkling, spraying, and diffusing
With means to vibrate or jiggle discharge
By electric transducer
C239S584000, C239S600000, C251S129060, C310S328000
Reexamination Certificate
active
06315216
ABSTRACT:
PRIOR ART
The invention is based on an injector having a multilayer piezoelectric actuator for injection systems, in particular for common rail diesel injection systems, of motor vehicles. The body of the piezoelectric actuator has a square or rectangular cross-sectional contour and is seated, together with a two-legged prestressing bracket that is mounted along opposed outer sides of the actuator body, inside a longitudinal bore of the injector body. One such injector is known from German Patent DE 40 36 287 C2, for instance.
FIGS. 1A and 1B
, in a schematic longitudinal section A and a cross section B, schematically show one such injector, in which inside an injector body
2
, an actuator forming a multilayer piezoelectric body
1
is fastened resiliently, by means of two clamping brackets the two clamping brackets are embodied as spring bands
3
a,
3
b,
between their opposed face ends, in order to actuate a tappet (not shown) of the injector. The square actuator body
1
is seated in a cylindrical longitudinal bore
5
of the injector body
2
.
As the schematic cross-sectional view in
FIG. 1B
shows, electrodes and contact paths
4
are mounted on the long sides of the actuator body
1
. The long sides of the actuator body
1
that are used for contacting purposes are the ones along which the clamping brackets
3
a
,
3
b
do not lead.
It is known that piezoelectric actuators, as shown in
FIG. 1B
, can be made most economically in rectangular or square form. This is because the actuator bodies are produced in large panels and are then sawn apart at the end into individual actuators. Where a common rail injector has a short structural shape, with a rectangular or square piezoelectric actuator of this kind, the smallest possible outside diameter of the injector body in the cylinder head of an internal combustion engine is important. Typical outside diameters are about 19 to 21 mm. The actuator body, together with its prestressing bracket, the electrode contacting, and a high-pressure bore (not shown in
FIGS. 1A and 1B
) leading to the injector nozzle, must be accommodated within this diameter.
OBJECT AND ADVANTAGES OF THE INVENTION
It is an object of the invention to embody an injector of this generic type such that a powerful rectangular or square multilayer piezoelectric actuator, its prestressing brackets, and the high-pressure bore, can be accommodated in space-saving fashion inside an injector body having the aforementioned outside diameter.
According to the invention, by means of a rectangular or square inside bore with rounded corners, the actuator body of square or rectangular outer contour can be surrounded, together with its prestressing brackets, relatively closely by the inside bore of the injector body, and at the same time structural space for the high-pressure bore in the injector body is created.
In one exemplary embodiment, the high-pressure bore is located in the injector body along one of the sides of the actuator body, on which side there is no leg of the prestressing bracket. Furthermore, an oil leakage bore can be located opposite the high-pressure bore in the injector body, axially parallel to the longitudinal axis of the injector body.
It is important that the actuator body need not be square but can instead have a rectangular cross-sectional contour. In that case, the two legs of the prestressing bracket can extend along the two longer sides of the rectangle of the actuator body, in which case the contact paths are located on the other two sides, that is, the short sides of the rectangle, of the actuator body.
Alternatively, the internal longitudinal bore of the injector body can be designed such that both the legs of the prestressing bracket and the contact paths extend along the same sides of the rectangle of the actuator body.
Since the width of the legs of the prestressing bracket, measured perpendicular to the direction of the longitudinal axis of the injector body, can be less than the width of the associated sides of the actuator body, the cross-sectional shape of the inner longitudinal bore in the injector body can also be rounded, in such a way that two side walls of approximately circular cross section adjoin two parallel side walls of the internal longitudinal bore. This bore can likewise be produced by reaming, using a reaming tool, or by electrochemical erosion.
REFERENCES:
patent: 4471256 (1984-09-01), Igashira et al.
patent: 4750706 (1988-06-01), Schlagmuller
patent: 4803393 (1989-02-01), Takahashi
patent: 5004945 (1991-04-01), Tomita et al.
patent: 5094429 (1992-03-01), Dostert
patent: 5248087 (1993-09-01), Dressler
patent: 6085990 (2000-07-01), Augustin
patent: 4036287-A (1991-05-01), None
patent: 19548526-A (1997-07-01), None
patent: 19650900-A (1998-06-01), None
Ganey Steven J.
Greigg Ronald E.
Robert & Bosch GmbH
LandOfFree
Injector comprising a piezo multilayer actuator for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Injector comprising a piezo multilayer actuator for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Injector comprising a piezo multilayer actuator for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2611270