Fuel injection device for internal combustion engines

Details Fuel injection device for internal combustion engines Fuel injection device for internal combustion engines

1998-02-17

1999-11-02

Kashnikow, Andres

Fluid sprinkling, spraying, and diffusing

Unitary injection nozzle and pump or accumulator plunger

239 90, 239585, F02M 4702

Patent

active

059754281

DESCRIPTION:

BRIEF SUMMARY
PRIOR ART

The invention is based on a fuel injection device for internal combustion engines. In a fuel injection device of this type, known from British Patent GB 1 320 057, the outflow conduit coming from the control chamber discharges into a collection chamber, which communicates with a relief chamber via a relief line leading onward. The valve seat for the valve member of the control valve is provided at the inlet of the outflow conduit into this collection chamber. As its drive mechanism, this valve member has a piezoelectric element and is embodied as a valve member with a conical sealing face. This valve performs the function of controlling the pressure in the control chamber, taking into account the fact that if a piezoelectric element is to function operationally reliably, it cannot be acted upon except by pressure. In this regard, the closing force transmitted by the valve seat and the resultant force, which is exerted on the valve member from the pressure relief via the cross section of the outflow conduit, act upon the piezoelectric element. Some of the work capacity of the piezoelectric element is then lost, because it has to furnish of the closing force.


Advantages of the Invention

The fuel injection device according to the invention, has the advantage that the closing force required for tightly closing the control valve need not be brought to bear by the piezoelectric element but instead is generated by the pressure in the control chamber. A high adjusting force to be brought to bear by the piezoelectric element is necessary only for opening the valve, and once again the piezoelectric element is acted upon by the adjusted pressure in the control chamber. As soon as the valve has opened, the force counteracting the adjusting motion or the opening of the control valve is rapidly diminished, so that in this case as well the piezoelectric element does not undergo any substantial stress. Thus in the embodiment of the invention the piezoelectric element that actuates the control valve can be substantially smaller, and the requisite energy can be kept slighter. In the closing position of the valve, the result is a self-sealing function, because of the fact that in this position, the high fuel pressure delivered via the inlet always prevails in the control chamber.
In an advantageous further feature, the space required for the adjusting motion of the valve member in the opening direction is reduced to the region of a recess, so that the diameter of the control piston can be kept small, which in turn has the advantage that higher speeds of the fuel injection valve member can be attained, since the volumetric flow to be forced in and out of the control chamber is less.
In another advantageous feature, two valve seats in line with one another are provided in the course of the outflow for relieving the pressure of the control chamber via the outflow conduit. Upon an adjusting motion of the valve member in the direction of the control chamber, the valve formed by the valve member and the first valve seat is opened, and as a consequence the valve formed by the valve member and the second valve seat is closed. When the valve member rests with its sealing face on the first valve seat, the pressure in the control chamber is built up in the sense of closing the fuel injection valve. If the injection valve is to move to the opening position, then upon an actuation of the piezoelectric element the valve member lifts up from the first valve seat. In this process, it can remain in an intermediate position, in which the flow cross section at both valve seats is opened. In this position, the injection valve member of the fuel injection valve can move to the opening position, so that a fuel injection takes place that is determined by the length of time that the valve member of the control valve remains in this position. Conversely, if the piezoelectric element is triggered such that it can execute its full actuation stroke, then after the cross section at the first valve seat opens the valve member of the control

REFERENCES:
patent: 4527737 (1985-07-01), Deckard
patent: 4566416 (1986-01-01), Berchtold
patent: 4964571 (1990-10-01), Taue et al.
patent: 5042718 (1991-08-01), Bergmann et al.
patent: 5275337 (1994-01-01), Kolarik et al.

Affiliated with

Also associated with

Rating

Fuel injection device for internal combustion engines does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Fuel injection device for internal combustion engines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fuel injection device for internal combustion engines will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2124386