Fuel system for internal combustion engine and a method to lessen pressure fluctuations in a fuel filter device in a fuel system

• US 10,450,990 B2
• Filed: 06/12/2015
• Issued: 10/22/2019
• Est. Priority Date: 07/08/2014
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Cedfors, Dan
• Primary Examiner(s): Solis, Erick R
• Assistant Examiner(s): Bacon, Anthony L
• Application Number:
  US15/319,290
• Publication Number:
  US 20170130665A1
• Time in Patent Office: 1,593 Days
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 29/02 peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers
• CPC Class Codes: F02D 33/006 depending on engine operating conditions, e.g. start, stop or ambient conditions
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02D 41/3082 Control of electrical fuel pumps
• CPC Class Codes: F02D 41/3836 Controlling the fuel pressure
• CPC Class Codes: F02M 37/0047 Layout or arrangement of systems for feeding fuel fuel injection apparatus characterised by their conduits and venting means F02M55/00; fuel injection apparatus having a common rail F02M63/0225; arrangement of fuel conduits of low pressure fuel injection apparatus F02M69/462
• CPC Class Codes: F02M 37/0052 Details on the fuel return circuit; Arrangement of pressure regulators
• CPC Class Codes: F02M 37/0088 Multiple separate fuel tanks or tanks being at least partially partitioned
• CPC Class Codes: F02M 37/08 electrically driven
• CPC Class Codes: F02M 37/20 characterised by means for preventing vapour lock
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop

Abstract

A fuel system for an internal combustion engine is provided, which comprises a first fuel tank, a fuel filter device, arranged between a low pressure pump operated by an electric motor and a high pressure pump, a first fuel conduit, through which the low pressure pump is arranged to supply fuel to the fuel filter device, and a control device, arranged in connection with an electric motor operating the low pressure pump. An overflow conduit is arranged in connection with a deaeration outlet, arranged in the fuel filter device and the first fuel tank, and the control device is arranged to control the electric motor, in such a way that the low pressure pump is active when the internal combustion engine is turned off for a limited period, whereby fuel may flow from the fuel filter device via the deaeration outlet and the overflow conduit, back to the first fuel tank.

Claims

1. A fuel system for an internal combustion engine, which fuel system comprises:

a first fuel tank;

a fuel filter device, arranged between a low pressure pump operated by an electric motor and a high pressure pump;

a first fuel conduit, through which the low pressure pump is arranged to supply fuel to the fuel filter device;

a deaeration outlet associated with the fuel filter device;

an overflow conduit arranged in connection with the deaeration outlet and the first fuel tank; and

a control device arranged in connection with the electric motor, operating the low pressure pump,

wherein the control device is arranged to control the electric motor, in such a way that the low pressure pump is active for a limited period after the internal combustion engine is turned off, and

wherein the control device is arranged to reduce the rotational speed of the low pressure pump when the internal combustion engine is turned off, thereby ensuring that fuel flows from the fuel filter device back to the first fuel tank, via the deaeration outlet arranged in the fuel filter device, and the overflow conduit arranged in connection with the deaeration outlet and the first fuel tank.

2. A fuel system according to claim 1, wherein the control device is arranged to deactivate the low pressure pump when the internal combustion engine has been turned off for a predetermined period.

3. A fuel system according to claim 1, wherein the fuel filter device comprises a filter house, wherein a filter element is arranged.

4. A fuel system according to claim 1 further comprising a ventilation device arranged at the deaeration outlet of the fuel filter device.

5. A fuel system according to claim 4, wherein the ventilation device consists of a throttle valve.

6. A fuel system according to claim 1, wherein the deaeration outlet is arranged in the fuel filter device in such a way that the fuel bypasses the filter element before passing through the deaeration outlet.

7. A fuel system according to claim 1, wherein the deaeration outlet is arranged in the fuel filter device in such a way that fuel passes through the filter element before passing through the deaeration outlet.

8. A combustion engine comprising a fuel system, wherein said fuel system comprises:

a first fuel tank;

a fuel filter device, arranged between a low pressure pump operated by an electric motor and a high pressure pump;

a first fuel conduit, through which the low pressure pump is arranged to supply fuel to the fuel filter device;

a deaeration outlet associated with the fuel filter device;

an overflow conduit arranged in connection with the deaeration outlet and the first fuel tank; and

a control device arranged in connection with an electric motor, operating a low pressure pump;

wherein the control device is arranged to control the electric motor, in such a way that the low pressure pump is active for a limited period after the internal combustion engine is turned off, and

wherein the control device is arranged to reduce the rotational speed of the low pressure pump when the internal combustion engine is turned off, thereby ensuring that fuel flows from the fuel filter device back to the first fuel tank, via the deaeration outlet arranged in the fuel filter device, and the overflow conduit arranged in connection with the deaeration outlet and the first fuel tank.

9. A combustion engine according to claim 8, wherein the control device of the fuel system is arranged to deactivate the low pressure pump when the internal combustion engine has been turned off for a predetermined period.

10. A combustion engine according to claim 8, wherein the fuel system comprises a ventilation device arranged at the deaeration outlet of the fuel filter device.

11. A combustion engine according to claim 8, wherein the deaeration outlet is arranged in the fuel filter device of the fuel system in such a way that the fuel bypasses the filter element before passing through the deaeration outlet.

12. A combustion engine according to claim 8, wherein the deaeration outlet is arranged in the fuel filter device of the fuel system in such a way that fuel passes through the filter element before passing through the deaeration outlet.

13. A vehicle, comprising a fuel system for an internal combustion engine, wherein the fuel system comprises:

a first fuel tank;

a fuel filter device, arranged between a low pressure pump operated by an electric motor and a high pressure pump;

a first fuel conduit, through which the low pressure pump is arranged to supply fuel to the fuel filter device;

a deaeration outlet associated with the fuel filter device;

an overflow conduit arranged in connection with the deaeration outlet and the first fuel tank; and

a control device arranged in connection with an electric motor, operating a low pressure pump;

wherein the control device is arranged to control the electric motor, in such a way that the low pressure pump is active for a limited period after the internal combustion engine is turned off, and

wherein the control device is arranged to reduce the rotational speed of the low pressure pump when the internal combustion engine is turned off, thereby ensuring that fuel flows from the fuel filter device back to the first fuel tank, via the deaeration outlet arranged in the fuel filter device, and the overflow conduit arranged in connection with the deaeration outlet and the first fuel tank.

14. A vehicle according to claim 13, wherein the control device of the fuel system is arranged to deactivate the low pressure pump when the internal combustion engine has been turned off for a predetermined period.

15. A vehicle according to claim 13, wherein the fuel system comprises a ventilation device arranged at the deaeration outlet of the fuel filter device.

16. A vehicle according to claim 13, wherein the deaeration outlet is arranged in the fuel filter device of the fuel system in such a way that the fuel bypasses the filter element before passing through the deaeration outlet.

17. A vehicle according to claim 13, wherein the deaeration outlet is arranged in the fuel filter device of the fuel system in such a way that fuel passes through the filter element before passing through the deaeration outlet.

18. A method to lessen pressure fluctuations in a fuel filter device in a fuel system for an internal combustion engine, which fuel system comprises a first fuel tank, a fuel filter device, arranged between a low pressure pump operated by an electric motor and a high pressure pump, a first fuel conduit, via which the low pressure pump is arranged to supply fuel to the fuel filter device, a deaeration outlet associated with the fuel filter device, an overflow conduit arranged in connection with the deaeration outlet and the first fuel tank, and a control device, arranged in connection with an electric motor operating the low pressure pump, wherein the method comprises the steps:

a) identifying shutdown of the internal combustion engine;

b) ensuring that the low pressure pump is active for a limited period after the internal combustion engine is turned off, with the use of the control device, wherein said ensuring comprises reducing the rotational speed of the low pressure pump when the internal combustion engine is turned off; and

c) ensuring that fuel flows from the fuel filter device back to the first fuel tank, via the deaeration outlet arranged in the fuel filter device, and the overflow conduit arranged in connection with the deaeration outlet and the first fuel tank.

19. A method according to claim 18, wherein step c) comprises providing a ventilation device at the deaeration outlet of the fuel filter device.

20. A method according to claim 18, the method further comprising the step to:

d) deactivate the low pressure pump by turning off the electric motor after a predetermined period of time.