Fluid sprinkling – spraying – and diffusing – Fluid pressure responsive discharge modifier* or flow... – Fuel injector or burner
Patent
1997-10-10
1999-08-10
Kashnikow, Andres
Fluid sprinkling, spraying, and diffusing
Fluid pressure responsive discharge modifier* or flow...
Fuel injector or burner
267180, F02M 6120
Patent
active
059345721
DESCRIPTION:
BRIEF SUMMARY
PRIOR ART
The invention is based on a fuel injection valve for fuel injection engines. In one such fuel injection valve, known from German Patent 29 43 744, a valve member is guided axially displaceably in a valve body. On one end, toward the combustion chamber, the valve member has a valve sealing face, with which it cooperates with a stationary valve seat on the valve body for the sake of controlling an injection cross section. On its other end, remote from the combustion chamber, the valve member is acted upon by a valve spring, which presses the valve member into contact with the valve seat. This valve spring is inserted into a spring chamber inside the housing of the injection valve, in this case in a retaining body, and is braced with its end remote from the valve member on a stationary stop face. The valve spring is embodied as a helical spring, whose windings of spring wire have a circular cross section.
The spring force of the valve spring determines the opening pressure at the injection valve, which is built up from the high fuel pressure engaging the valve member in the opening direction. The capacity or spring force of the valve spring thus has major significance; this spring force is dependent essentially on the cross-sectional area of the wire at the windings. If the spring force is to be increased, it is usual with conventional round wire to increase the wire thickness, so that its maximum cross-sectional area is the result of the predetermined outside and inside diameter of the winding cross section.
The known fuel injection valve has the disadvantage, however, that increasing the wire thickness or axially lengthening the valve spring in order to increase the spring force meets with structural limits, since the existing installation space for the spring chamber is limited and cannot be increased without making extensive changes in the injection valve, so that increasing the spring force of the valve spring is not possible without making complicated changes in the injection valve.
ADVANTAGES OF THE INVENTION
The fuel injection valve according to the invention for internal combustion engines, has the advantage over the prior art that the spring force of the valve spring can be increased without increasing the required installation space for the valve spring in the housing of the injection valve; this advantage is especially pronounced in springs with a very small inside diameter and hence a low winding ratio (Dm/y up to 2.5).
This becomes advantageously possible in that the valve spring, embodied as a helical spring, is made of thicker spring wire with an increased basic cross section at the windings and is then ground down on the outside diameter far enough that the valve spring can just be inserted into the cylindrical spring chamber, in which it then has only as much play relative to the inner wall as is needed when the valve spring is compressed. The initially circular basic cross section of the spring windings then has ground faces on its ends pointing radially outward with respect to the spring axis, and these ground faces are oriented parallel to the spring axis and to the wall of the spring chamber.
In this way, while the installation space for the valve spring remains the same, greater opening pressures can be attained, and in the case where two valve springs that come into play successively are used, in so-called two-spring holders, greater opening pressure differences can be achieved.
In addition, the tolerance in terms of the outer diameter of the valve spring can be reduced to a minimum amount, compared with unmachined springs.
The valve spring embodied according to the invention has the advantage over alternative wire cross sections, such as rectangular, elliptical or other shaped wires, that the wire production involves no additional expense, and the valve spring can thus be produced more easily and economically than the aforementioned versions. Moreover, by the subsequent grinding down of the outer diameter of the valve spring, more accurate outer diameters of the spring a
REFERENCES:
patent: 2521670 (1950-09-01), Starkey et al.
patent: 2586646 (1952-02-01), Graham
patent: 2622448 (1952-12-01), Lorig
patent: 3511280 (1970-05-01), Mercier
patent: 3727902 (1973-04-01), Burckhardt et al.
patent: 5165607 (1992-11-01), Stevens
Hofmann Karl
Kuegel Peter
Oezyesilova Ibrahim
Douglas Lisa A.
Greigg Edwin E.
Greigg Ronald E.
Kashnikow Andres
Robert & Bosch GmbH
LandOfFree
Control spring for a fuel injection valve for internal combustio does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control spring for a fuel injection valve for internal combustio, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control spring for a fuel injection valve for internal combustio will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1111488