Pumps – With condition responsive pumped fluid control – Inlet throttle or stop valve
Patent
1998-07-27
2000-08-08
Freay, Charles G.
Pumps
With condition responsive pumped fluid control
Inlet throttle or stop valve
417310, 417440, F02N 4112, F04B 4900
Patent
active
060992638
DESCRIPTION:
BRIEF SUMMARY
PRIOR ART
The invention is based on a fuel delivery pump for a fuel injection pump for internal combustion engines.
EP 0 166 995 B1 has disclosed a fuel delivery pump of this kind embodied as a gear delivery pump, which feeds the fuel from a storage tank into the intake chamber of a fuel injection pump. To that end, the delivery pump has a pair of gears that mesh with external engagement, which delivers fuel from an intake chamber connected to the storage tank via an intake line, into a pressure chamber connected to the intake chamber of the fuel injection pump via a supply line. To control the pressure in the pressure chamber or the feed quantity to the fuel injection pump, a bypass conduit is provided between the pressure chamber and the intake chamber of the fuel delivery pump. The opening of this bypass conduit is carried out by means of a pressure valve inserted in the bypass conduit, which valve unblocks a particular opening cross section as a function of the spring force of the valve spring when there is a particular pressure difference between the pressure chamber and the intake chamber. The opening time of the pressure valve can be set via the initial force of the valve spring, which is why the axial position of the abutment of the pressure valve spring can be adjusted.
The known fuel delivery pump, however, has the disadvantage that the bypass conduit that contains the pressure valve is disposed outside the delivery pump or spatially speaking, relatively far from the gear pair, which results in an increase in construction and assembly costs as well as taking up a lot of space.
The German Patent Application P 44 41 505.2 has disclosed a fuel delivery pump which avoids the above mentioned disadvantages. The bypass conduit that contains the pressure valve is integrated into the housing of the delivery pump so that no additional space is required.
Both fuel delivery pumps, however, have the disadvantage that when the fuel delivery pump is shut off, the fuel present in the pump chamber can flow into the intake line leading to the fuel delivery pump and the fuel delivery pump can empty. As a result, sometimes the intake line has to be ventilated when restarting.
ADVANTAGES OF THE INVENTION
The fuel delivery pump according to the invention for a fuel injection pump for internal combustion engines has the advantage over the prior art that a check valve that can close the intake chamber of-the fuel delivery pump prevents the fuel delivery pump from emptying when the motor is shut off. As a result, immediately after restarting, fuel can be delivered to the fuel delivery pump of the fuel injection pump so that the required delivery pressure for the fuel can be built up within a short time. Consequently, the disposition of a check valve which closes the intake chamber can achieve a higher efficiency when starting. It is furthermore advantageous that the fuel delivery pump remains wet with fuel when the motor is shut off so that no corrosion can occur. It is particularly advantageous to dispose the check valve in an opening that leads to the intake chamber so that a fuel delivery pump can be embodied with a small amount of space.
The check valve that closes the intake chamber furthermore has the advantage of functioning as a flow resistor with a throttling action during operation of the fuel delivery pump. Through the throttling of the fuel in the intake line, the delivery flow can be reduced with increasing speed. As a result, a gentle transition can be achieved from the steadily increasing delivery flow to the maximal delivery flow, by means of which a low amount of operating power is required to deliver the fuel. The excess quantity is usually diverted via a pressure limiting valve. This makes it possible for the characteristic curve of the pump to have the ability to be adapted to a required characteristic curve, by means of which due to the smaller throttled quantity, a less intense heating of the fuel delivery pump can be achieved. At the same time, the check valve functions as a suction throttle wh
REFERENCES:
patent: 2310078 (1943-02-01), Herman
patent: 2397480 (1946-04-01), Fullerton, Jr.
patent: 2481646 (1949-09-01), Conklin
patent: 3146720 (1964-09-01), Henry
patent: 3935917 (1976-02-01), Eley et al.
patent: 4013053 (1977-03-01), Dinkelkamp et al.
patent: 4200207 (1980-04-01), Akers et al.
patent: 4443161 (1984-04-01), Masuda et al.
patent: 4569202 (1986-02-01), Mouton
patent: 4902202 (1990-02-01), Bowden
patent: 4968218 (1990-11-01), Koivula et al.
patent: 5018947 (1991-05-01), Tsuboi
patent: 5338161 (1994-08-01), Eley
patent: 5381723 (1995-01-01), Nilsson et al.
patent: 5397219 (1995-03-01), Cretors
patent: 5411375 (1995-05-01), Bauer
patent: 5597291 (1997-01-01), Bodzak et al.
patent: 5722738 (1998-03-01), Beck et al.
patent: 5823639 (1998-10-01), Zinnkann et al.
Bodzak Stanislaw
Mayer Hanspeter
Evora Robert Z.
Freay Charles G.
Greigg Edwin E.
Greigg Ronald E.
Robert & Bosch GmbH
LandOfFree
Fuel delivery pump with a bypass valve and an inlet check valve 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 delivery pump with a bypass valve and an inlet check valve , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fuel delivery pump with a bypass valve and an inlet check valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1144372