System and methods for refueling a vehicle

Patent metadata

Field	Value
Publication number	US-9644552-B2
Application number	US-201414313646-A
Country	US
Kind code	B2
Filing date	Jun 24, 2014
Priority date	Jun 24, 2014
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A method for a fuel system, comprising: during a first condition, fluidly coupling a fuel tank to a fuel vapor canister; and fluidly coupling the fuel vapor canister to atmosphere via a deactivated vacuum pump. By fluidly coupling the fuel vapor canister to atmosphere via a deactivated vacuum pump, the fuel tank may be depressurized slowly without requiring a multi-stage or multi-valve fuel tank isolation system. In this way, the cost and complexity of the fuel system is reduced.

First claim

The invention claimed is:

1. A method for a fuel system, comprising:
responsive to a refueling request and prior to allowing access to a fuel filler neck, fluidly coupling a fuel tank to a fuel vapor canister by opening a valve;
fluidly coupling the fuel vapor canister to atmosphere via a deactivated vacuum pump, where the fuel vapor canister is fluidly coupled to atmosphere via the deactivated vacuum pump further responsive to a fuel tank pressure above a first threshold;
responsive to the fuel tank pressure decreasing below the first threshold, fluidly coupling the fuel vapor canister to atmosphere bypassing the deactivated vacuum pump,
where the deactivated vacuum pump is coupled within an evaporative leak check module comprising a changeover valve operable between a first conformation and a second conformation,
where fluidly coupling the fuel vapor canister to atmosphere via the deactivated vacuum pump comprises placing the changeover valve in the second conformation, and
where fluidly coupling the fuel vapor canister to atmosphere bypassing the deactivated vacuum pump comprises placing the changeover valve in the first conformation; and

responsive to a fuel tank depressurization rate being less than a depressurization threshold, pulsing the changeover valve between the first conformation and the second conformation.

2. The method of claim 1 , further comprising if a depressurization rate of the fuel tank is less than a threshold when the fuel vapor canister is coupled to atmosphere via the deactivated vacuum pump, pulsing the changeover valve, where the fuel vapor canister is fluidly coupled to atmosphere bypassing the deactivated vacuum pump each time the changeover valve is pulsed.

3. The method of claim 1 , where the valve that is opened to fluidly couple the fuel tank to the fuel vapor canister is a fuel tank isolation valve.

4. The method of claim 1 , further comprising:
responsive to the fuel tank pressure decreasing below the first threshold, placing the changeover valve in the first conformation.

5. The method of claim 4 , further comprising:
responsive to the fuel tank pressure decreasing below a second threshold, the second threshold less than the first threshold, removing access restrictions to the fuel filler neck.

6. A method for refueling a vehicle, comprising:
responsive to a refueling request and prior to allowing access to a fuel filler neck, and during a condition where a fuel tank pressure is greater than a first threshold, opening a fuel tank isolation valve coupled between a fuel tank and a fuel vapor canister;
fluidly coupling the fuel vapor canister to atmosphere via a deactivated vacuum pump;
responsive to the fuel tank pressure decreasing below the first threshold, fluidly coupling the fuel vapor canister to atmosphere bypassing the deactivated vacuum pump, where fluidly coupling the fuel vapor canister to atmosphere bypassing the deactivated vacuum pump comprises placing an evaporative leak check module changeover valve in a first conformation, and where fluidly coupling the fuel vapor canister to atmosphere via the deactivated vacuum pump comprises placing the evaporative leak check module changeover valve in a second conformation; and
responsive to a fuel tank depressurization rate being less than a depressurization threshold, pulsing the evaporative leak check module changeover valve between the first conformation and the second conformation.

7. A method for a fuel system, comprising:
during a first condition, fluidly coupling a fuel tank to a fuel vapor canister;
fluidly coupling the fuel vapor canister to atmosphere via a deactivated vacuum pump, where the first condition comprises a refueling request and a fuel tank pressure above a first threshold;
responsive to the fuel tank pressure decreasing below the first threshold, fluidly coupling the fuel vapor canister to atmosphere bypassing the deactivated vacuum pump,
where the deactivated vacuum pump is coupled within an evaporative leak check module comprising a changeover valve operable between a first conformation and a second conformation and where fluidly coupling the fuel vapor canister to atmosphere via the deactivated vacuum pump comprises placing the changeover valve in the second conformation where fluidly coupling the fuel vapor canister to atmosphere bypassing the deactivated vacuum pump comprises placing the changeover valve in the first conformation; and
responsive to a fuel tank depressurization rate being less than a depressurization threshold, pulsing the changeover valve between the first conformation and the second conformation.

8. The method of claim 7 , where fluidly coupling the fuel tank to the fuel vapor canister comprises opening a fuel tank isolation valve.

Assignees

• Ford Global Tech Llc

Inventors

• Dudar Aed M

Classifications

• F02M25/0818

  having means for pressurising the evaporative emission space · CPC title

• F16K21/18

  closed when a rising liquid reaches a predetermined level (float-actuated valves F16K31/18) · CPC title

• F02D41/042

  for stopping the engine · CPC title

• F17C2227/04

  Methods for emptying or filling · CPC title

• F17C5/02

  for filling with liquefied gases · CPC title