Internal-combustion engines – Charge forming device – With fuel pump
Patent
1991-06-07
1992-09-29
Miller, Carl S.
Internal-combustion engines
Charge forming device
With fuel pump
123449, F02M 3704
Patent
active
051506882
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention is based on a magnet valve as defined hereinafter. In such a magnet valve, known from German Patent 25 03 345, the closing element is coupled to the armature of the magnet valve via a drag coupling, and the armature is embodied with its face end that plunges into the closing part as a valve element, so that this element blocks the communication between the intake line parts via the bore whenever the armature, under the influence of the restoring spring, moves or has moved the closing part into the closing position. Upon opening of the magnet valve the armature is lifted from its seat on the closing part under the influence of the magnetic force of the electromagnet, opens the bore, and only in the course of a further stroke lifts the closing part from its seat via the drag coupling, so that the force for opening the closing part, which is acted upon by both the restoring spring and the pressure prevailing upstream of the seat in the intake line, can be kept small, because a pressure equalization is effected previously via the bore.
Under certain conditions, however, it may happen with a magnet valve of this generic type that the closing part, when it is moved to the closing position, is acted upon by a pressure pulse from the pump work chamber in the course of the remaining delivery stroke of the fuel injection pump and after opening of the communication between the intake line and the pump work chamber. This pressure pulse can cause the closing part to be lifted from its seat, so that a process of refilling the pump work chamber can briefly take place via the intake line. This quantity flowing through the pump work chamber can also be brought to injection in the next delivery stroke of the pump piston, and thus the purpose of the magnet valve, which is to serve for the purpose of shutoff, is not attained. In particular, with such a defect in the control of the fuel injection pump, the internal combustion engine can race.
ADVANTAGES OF THE INVENTION
A magnet valve according to the invention has the advantage over the prior art that pushing open of the closing part and thus a correspondingly large flow of fuel to the pump work chamber is prevented, since the pressure pulse is reduced via the open valve member, which opens only a small overflow cross section.
By the provisions recited in the specification further advantageous developments of and improvements will become apparent. A small valve member with flow mass is the result which can reach its closing position again with low inertia, so that there is only a minimal reverse flow effect after the valve member has been pushed open. The disadvantages referred to at the outset are thus avoided to the greatest possible extent .
DRAWINGS
One exemplary embodiment of the invention is shown in the drawing, and will be described in further detail in the ensuing description.
FIG. 1 is a fragmentary longitudinal section through a fuel injection pump, in which magnet valve according to the invention is used;
FIG. 2 is a fragmentary section through FIG. 1 along the line II--II; and
FIG. 3 is a longitudinal section through the magnet valve according to the invention, on a larger scale.
DESCRIPTION OF THE EXEMPLARY EMBODIMENT
In the fuel injection pump shown in FIG. 1 for multi-cylinder internal combustion engines, a cylinder liner 2 is inserted into a housing 1, and in its cylinder bore 3, a pump piston 4 is set into simultaneously reciprocating and rotating motion, as indicated by the arrows in the drawing, by a drive mechanism and cam drive, not further shown, of the fuel injection pump. In the cylinder bore 3, the pump piston 4 on its face end encloses a pump work chamber 6, which is supplied with fuel in the intake stroke of the pump piston via longitudinal grooves 8, which serve as filling grooves, originating at the face end 7 of the pump piston. As can be seen from FIG. 2, which is a section through FIG. 1 along the line II--II, the filling grooves 8 are distributed at uniform angular intervals around the jacke
REFERENCES:
patent: 4412519 (1983-11-01), Hoch
patent: 4491111 (1985-01-01), Eheim
patent: 4563133 (1986-01-01), Yasuhara
patent: 4617959 (1986-10-01), Yamada
patent: 4723570 (1988-02-01), Baba
patent: 4753212 (1988-06-01), Miyaki
patent: 4793314 (1988-12-01), Yoshinaga
patent: 4832311 (1989-05-01), Kiwura
patent: 4840155 (1989-06-01), Karle
patent: 4974564 (1990-12-01), Laufer
patent: 5007400 (1991-04-01), Babitzka
Alvarez-Avila Carlos
Nothdurft Heinz
Sprenger Kurt
Trunk Reinhard
Greigg Edwin E.
Greigg Ronald E.
Miller Carl S.
Robert & Bosch GmbH
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