Systems and methods for a fuel refill pressure relief valve

Patent metadata

Field	Value
Publication number	US-12305776-B2
Application number	US-202318330924-A
Country	US
Kind code	B2
Filing date	Jun 7, 2023
Priority date	Jun 7, 2023
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

Methods and systems are provided for diagnosing a fuel refill pressure relief valve that is located along a passage that extends from an exhaust system to a fuel tank. The method may include commanding the fuel refill pressure relief valve open while monitoring flow through particulate filter via a differential pressure sensor.

First claim

The invention claimed is:

1. A method for an engine, comprising:
activating a pump and commanding a fuel refill pressure relief valve open in response to a request to diagnose the fuel refill pressure relief valve, the fuel refill pressure relief valve located along a first passage between an engine exhaust system and a fuel tank;
opening a fuel tank isolation valve in response to the request to diagnose the fuel refill pressure relief valve;
monitoring a flow through an emissions device, wherein the pump is positioned along a second passage between a carbon filled canister and an atmospheric opening;
indicating degradation of the fuel refill pressure relief valve in response the flow being less than a threshold flow and indicating an absence of degradation in response to the flow being greater than the threshold flow; and
closing or holding closed all exhaust valves of the engine in response to the request to diagnose the fuel refill pressure relief valve.

2. The method of claim 1 , wherein the engine is coupled in a hybrid vehicle.

3. The method of claim 1 , wherein the engine is coupled in a plug-in hybrid vehicle.

4. The method of claim 1 , further comprising judging whether or not there is a request to refill the fuel tank, wherein a user may press a button to indicate that refueling is requested.

5. A system for a vehicle, comprising:
an internal combustion engine including an exhaust system;
a fuel tank;
a differential pressure sensor configured to sense pressure across a particulate filter;
an evaporative emissions system including a pump and a fuel refill pressure relief valve, the fuel refill pressure relief valve positioned along a first passage extending between the fuel tank and the exhaust system; and
a controller including executable instructions stored in non-transitory memory that cause the controller to diagnose the fuel refill pressure relief valve via activating the pump, and to monitor flow through the fuel refill pressure relief valve, wherein flow is monitored through the fuel refill pressure relief valve via the differential pressure sensor.

6. The system of claim 5 further comprising additional executable instructions that cause the controller to command open the fuel refill pressure relief valve to diagnose the fuel refill pressure relief valve.

7. The system of claim 6 ; further comprising a fuel tank isolation valve and additional executable instructions to command open the fuel tank isolation valve to diagnose the fuel refill pressure relief valve.

8. The system of claim 7 , where activating the pump causes gases to be drawn from the exhaust system to the pump.

9. A method for an engine, comprising:
closing exhaust valves of the engine and activating a pump in response to a request to diagnose a fuel refill pressure relief valve, the fuel refill pressure relief valve located along a first passage between an engine exhaust system and a fuel tank.

10. The method of claim 9 , further comprising monitoring flow through an emissions device in response to the request to diagnose the fuel refill pressure relief valve.

11. The method of claim 10 , wherein the engine is not combusting fuel and air.

12. The method of claim 11 , further comprising commanding open a fuel tank isolation valve.

13. The method of claim 12 , wherein the fuel tank isolation valve is located along a second passage, the second passage extending between a carbon filled canister and the fuel tank.

Assignees

• Ford Global Tech Llc

Inventors

• Dudar Aed

Classifications

• F02D13/0242

  Variable control of the exhaust valves only · CPC title

• F02M25/0809

  Judging failure of purge control system · CPC title

• F02M25/0836 Primary

  Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold · CPC title

• F02D41/22

  Safety or indicating devices for abnormal conditions {(in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809)} · CPC title

• F02D41/004

  Control of the valve or purge actuator, e.g. duty cycle, closed loop control of position · CPC title