Internal-combustion engines – Charge forming device – Fuel flow regulation between the pump and the charge-forming...
Reexamination Certificate
1998-06-16
2001-08-07
Moulis, Thomas N. (Department: 3747)
Internal-combustion engines
Charge forming device
Fuel flow regulation between the pump and the charge-forming...
C417S198000, C137S527800
Reexamination Certificate
active
06269800
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a device for feeding fuel from a supply container to an internal combustion engine of a motor vehicle.
Devices of the above mentioned general type are known in the art. One of such devices is disclosed for example in the German patent document DE 42 24 981 A1. In this device the fuel which is returned to the supply container is branched from the feeding conduit in the flow direction of the fuel before a check valve and supplied through the return conduit of the check pump which extends near the cup bottom through the cup wall of the accumulating cup. In another fuel feeding device of this type disclosed in the German patent document DE 44 26 667 A1 the return conduit leads the fuel which is not used by the internal combustion engine, back into the supply container and supplies there the jet nozzle of the jet pump. The mixing pipe of the jet pump is formed of one piece with the cup wall of the collecting cup and located near the cup bottom, while the outlet opening of the mixing pipe is flush with the inner side of the cup wall.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a device for feeding fuel which has the advantage that the check valve flap, with the jet pump turned off, abuts against the output of the mixing pipe under the action of the fluid pressure produced by the fuel volume in the collecting cup and closes the mixing pipe outlet hermetically.
It is thereby guaranteed that the accumulating cup in condition with the internal combustion engine is stopped, remains filled, and the feeding pump during the start of the internal combustion engine, in which the jet pump can not feed the fuel because of failing fuel return flow, provides optimal suction conditions in the collecting cup also at the low filling level of the supply container. With the repeated operation of the jet pump, the check valve flap is turned away from the outlet of the mixing pipe by the fuel filling jet of the jet pump which is composed of the fuel exiting the jet nozzle and entrained from the supply container by the jet suction action, and as a result the check valve flap is retained in the turned off condition. When the internal combustion is stopped and the jet pump is set in operation, the check valve flap can again be placed on the output of the mixing pipe and close the collecting cup.
The inventive device for feeding of fuel is therefore designed so that the check valve flap which closes the output of the mixing pipe is arranged in the collecting cup and formed so that it is turnable by the fuel jet which is fed by the jet pump from the fuel from the supply container into the collecting cup against the fuel pressure in the accumulating cup, from the output of the mixing pipe.
In accordance with a preferable embodiment of the present invention, the inventive check valve flap can be formed in a simple manner by a closing member which overlaps the outlet of the mixing pipe and an angular lever which carries the closing member and is turnably supported in the collecting cup on a lever end remote from the closing member. The closing member is preferably formed as a shell shaped or bell shaped cap of the elastic material, which is placed with its cap end on the ring-shaped end side of the mixing pipe.
In accordance with a preferable embodiment of the present invention, means is provided in the jet pump, which prevent a direct striking of the fuel jet exiting from the jet nozzle with a high speed, against the check valve flap. With the low fuel level in the supply container, the suction opening of the jet pump during splashing of the fuel in the supply container because of the curved or inclined driving of the motor vehicle emerges predominantly from the fuel so that the fuel jet exiting the jet nozzle, here called the free jet, can not give away its energy in the region of the suction opening to the fuel volume before the mixing pipe and thereby no fuel is fed from the supply container. The energy-rich free jet acts however on the check valve flap and holds it open, so that with stepping the fuel feeding in the collecting cup the collecting cup is empted with the open check valve flap through the mixing pipe and thereby the fuel feeding to the internal combustion engine is interrupted. The inventive means hold the free jet from the check valve flap, so that when the suction pump emerges from the fuel it closes because of the failing force action and during splashes of the fuel the accumulating cup is filled.
In accordance with preferable embodiment of the invention, the above mentioned means specifically is formed has an impact body arranged centrally in the mixing pipe and having a diameter which is greater than the jet cross-section of the free jet. Therefore, the free jet is prevented from directly striking against the check valve flap, however not with a fuel filling jet of the jet pump emerging in the fuel volume, whose cross-section corresponds to the throughgoing cross-section of the mixing pipe and thereby flows over the impact body. With this fuel filling jet, as described, the return valve flap if lifted from the outlet of the mixing pipe, and the pumping of the fuel through the jet pump from the supply container into the collecting cup is performed without problems.
In accordance with an advantageous embodiment of the invention, the impact body is mounted on a holding web which extends diametrically through the mixing pipe. The holding web is formed of one piece with the mixing pipe or can form a yoke of a U-shaped holding bracket which is separately inserted in the mixing pipe.
In accordance with an alternative embodiment of the invention, an impact body can be formed as a semi-disk or semi-sphere with a convex surface facing the jet nozzle, as a cone with a cone tip facing the jet nozzle, or as a disk or a plate.
In accordance with an alternative embodiment of the invention the means for holding the free jet from the check valve flap is formed as at least one deviating body arranged in the jet nozzle. It deviates the free jet exiting the jet nozzle from the nozzle axis so that it is tangential to the inner wall of the mixing pipe.
In accordance with various embodiments of the invention, the deviating body can be inserted in a central nozzle opening of the jet nozzle, which produces a conically shaped expanding free jet, or several deviating bodies can be inserted in the central nozzle opening of the jet nozzle so that the free jet is subdivided into several partial jets which are located on a conical surface extending from the nozzle opening. In the later case preferably the deviating body is formed of one piece with the nozzle body of the jet nozzle, and inserted in the nozzle body from its end side from the openings extending at an acute angle to the nozzle axis and opening into the central nozzle opening.
In accordance with a preferable embodiment of the invention, in addition a tubular stop is provided in the mixing pipe near the mixing pipe outlet, which extends radially inwardly and is ring shaped. Also, the arrangement of the mixing pipe and the jet nozzle is selected so that the free jet and the individual partial jets of the free jets strike against the tubular stop. The energy of the free jet is reduced at the tubular stop and can not act on the check valve flap in the periphery reduced by the deviation of the mixing pipe inner rod.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
REFERENCES:
patent: 4340023 (1982-07-01), Creager
patent: 4397333 (1983-08-01), Liba et al.
patent: 4503885 (1985-03-01), Hall
patent: 4750522 (1988-06-01), Griffin et al.
patent: 5341840 (1994-08-01), Manson et al.
patent: 5622205 (1
Fischerkeller Rolf
Liskow Uwe
Moulis Thomas N.
Robert & Bosch GmbH
Striker Michael J.
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