Fuel supply apparatus for an internal combustion engine of a motor vehicle

• US 6,457,459 B1
• Filed: 10/18/2000
• Issued: 10/01/2002
• Est. Priority Date: 10/19/1999
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Woerz, Stefan, Braun, Hans-Peter, Schelhas, Peter
• Primary Examiner(s): Wolfe, Willis R.
• Assistant Examiner(s): Gimie, Mahmoud
• Application Number:
  US09/691,360
• Time in Patent Office: 713 Days
• Field of Search: 123/514, 123/509, 123/510, 123/511, 123/497, 137/565.34
• US Class Current: 123/514
• CPC Class Codes: F02M 37/0023 Valves in the fuel supply and return system
• CPC Class Codes: F02M 37/0052 Details on the fuel return circuit; Arrangement of pressure regulators
• CPC Class Codes: F02M 37/0082 Devices inside the fuel tank other than fuel pumps or filters electrical pumps submerged in fuel tanks F02M37/10, jet pumps F02M37/025
• CPC Class Codes: F02M 37/025 Feeding by means of a liquid fuel-driven jet pump jet pumps per se F04F
• CPC Class Codes: F02M 37/106 the pump being installed in a sub-tank

Abstract

The fuel supply apparatus has a reservoir (14) arranged within a fuel tank (12) from which fuel is drawn by a fuel feed unit (16) and supplied to an internal combustion engine (10). Unburned fuel from the internal combustion engine (10) is fed back into the fuel tank (12) via a return line (30). A control valve (34) is arranged in the return line (30), by which a connection of the return line (30) with a jet pump (38) is controlled, which supplies fuel from the fuel tank (12) to the reservoir (14). The control valve (34) has a floating body floating on the fuel in the reservoir (14) when it is nearly filled or completely filled, by which a control element of the control valve (34) is movable. When the reservoir (14) is not in its maximum filled state (hmax) the jet pump (38) is connected with the return line (30), but when the reservoir (14) is in its maximum filled state (hmax) the jet pump (38) is disconnected from the return line (30), which then opens into the reservoir (14). Overflow of fuel from the reservoir when it is filled is thereby reduced.

Claims

1. A fuel supply apparatus for an internal combustion engine of a motor vehicle, said fuel supply apparatus comprising

a fuel tank (12) arranged in the motor vehicle;

a reservoir (14) arranged within the fuel tank (12);

a fuel feed unit (16) for drawing fuel from the reservoir (14) and feeding said fuel to the internal combustion engine (10);

a return line (30) connected with the internal combustion engine (10) for feeding back a part of the fuel supplied by the fuel feed unit (16) to the internal combustion engine and not burned by the internal combustion engine to the fuel tank;

a jet pump (38) connected with the return line (30) and comprising means for feeding said part of said fuel returned from the internal combustion engine into the reservoir (14);

a control valve (34) arranged in the return line (30) upstream from the jet pump, said control valve (34) comprising a floating body (70) arranged to float in said fuel in the reservoir (14) when the reservoir in nearly or completed filled and a control element (58) connected with said floating body (70) so that said control element (58) moves when a level of said fuel in said reservoir changes, whereby in a first position of the control element (58) when the reservoir (14) is not nearly in a filled state a connection is made between the jet pump (38) and the return line (30) and in a second position when the reservoir is at least nearly in said filled state the connection between the jet pump (38) and the return line (30) is broken and the return line (30) is directly connected to said reservoir and opens into the reservoir (14).

2. The fuel supply apparatus as defined in claim 1, wherein said control valve (34) is integrated in said reservoir (14).

3. The fuel supply apparatus as defined in claim 1, further comprising a cover element (28) for the reservoir (14) and wherein said control valve (34) is integrated in said cover element (28).

4. The fuel supply apparatus as defined in claim 1, wherein said control valve (34) has a valve body (50) and said floating body (70) and said control element (58) are slidably mounted in said valve body (50).

5. The fuel supply apparatus as defined in claim 4, wherein said floating body (70) and said control element (58) are arranged at least approximately coaxial to each other in said valve body (50).

6. The fuel supply apparatus as defined in claim 1, further comprising means for pressure compensating said control element (58) so that no force due to a pressure existing in the return line (30) acts on said control element (58) in a motion direction thereof.

7. The fuel supply apparatus as defined in claim 1, wherein said control element is moved into said first position by a force of gravity acting on said control element.

8. The fuel supply apparatus as defined in claim 1, wherein said control valve (34) comprises an integrated pressure limiting valve (80) and said pressure limiting valve (80) is arranged upstream of the control element (58).

9. The fuel supply apparatus as defined in claim 8, wherein said pressure limiting valve (80) is arranged in the outlet of the control valve (34) into the reservoir (14).