# US 11,441,498 B1 · Method and system for reducing evaporative emissions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,498 B1 - Document ID: US11441498B1 - Status: Granted - Kind: B1 - Application number: 17/305,222 - Filed: 2021-07-01 - Granted: 2022-09-13 - Earliest claimed: 2021-07-01 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Aed Dudar - Web page: https://patentgrep.com/patent/US11441498B1 ## CPC - F02D 41/004: {Control of the valve or purge actuator, e.g. duty cycle, closed loop control of position} - F02D 41/0035: {to achieve a special effect, e.g. to warm up the catalyst} - F02M 25/0836: {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} - F02M 25/0854: {Details of the absorption canister} - F02D 2200/0602: Fuel pressure - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF ## Abstract Methods and systems are presented for controlling flow through a recirculation tube of an evaporative emissions system. The methods and systems may adjust flow through the recirculation tube by controlling an amount of time an evaporative emissions system valve is held open and held closed during refilling of a fuel tank. ## Claims ### Claim 1 A vehicle system, comprising: a vehicle including an internal combustion engine, a fuel tank, and an evaporative emissions system valve; and one or more controllers in the vehicle, the one or more controllers including executable instructions stored in non-transitory memory that cause the one or more controllers to open and close the evaporative emissions system valve during refilling of the fuel tank, adjust opening and closing the evaporative emissions system valve in response to a fuel tank pressure during refilling of the fuel tank, and increase an amount of time that the evaporative emissions valve is closed in response to a pressure in the fuel tank being less than a first threshold. ### Claim 2 (depends on 1) The vehicle system of claim 1, where the evaporative emissions system valve is a vapor blocking valve. ### Claim 3 (depends on 1) The vehicle system of claim 1, where the evaporative emissions system valve is a canister vent valve. ### Claim 4 (depends on 1) The vehicle system of claim 1, where the evaporative emissions system valve is opened and closed a plurality of times. ### Claim 5 (depends on 1) The vehicle system of claim 1, further comprising additional instructions to decrease an amount of time that the evaporative emissions valve is closed in response to a pressure in the fuel tank being greater than a second threshold. ### Claim 6 A method for operating an evaporative emissions system, comprising: repeatedly cycling an evaporative emissions system valve open and closed via a controller while a fuel tank is being filled. ### Claim 7 (depends on 6) The method of claim 6, where the evaporative emissions system valve is a canister vent valve, and further comprising adjusting timing at which the evaporative emissions system valve is repeatedly cycled open and closed. ### Claim 8 (depends on 6) The method of claim 6, where the evaporative emissions system valve is a vapor blocking valve, and further comprising adjusting timing at which the evaporative emissions system valve is repeatedly cycled open and closed. ### Claim 9 (depends on 8) The method of claim 8, where adjusting timing at which the evaporative emissions system valve is repeatedly cycled open and closed includes increasing an amount of time that the evaporative emissions system valve is closed in response to a pressure of the fuel tank being less than a first threshold pressure. ### Claim 10 (depends on 8) The method of claim 8, where adjusting timing at which the evaporative emissions system valve is repeatedly cycled open and closed includes decreasing an amount of time that the evaporative emissions system valve is closed in response to a pressure of the fuel tank being greater than a second threshold pressure. ### Claim 11 (depends on 8) The method of claim 8, where adjusting timing at which the evaporative emissions system valve is repeatedly cycled open and closed includes adjusting the timing in response to a pressure in a fuel tank. ### Claim 12 (depends on 6) The method of claim 6, further comprising holding open a canister vent valve while the fuel tank is being filled. ### Claim 13 (depends on 11) The method of claim 11, further comprising holding closed a canister purge valve while the fuel tank is being filled. ### Claim 14 A method for operating an evaporative emissions system, comprising: adjusting a flow through a recirculation tube of an evaporative emissions system via controller according to a pressure in a fuel tank while the fuel tank is being filled. ### Claim 15 (depends on 14) The method of claim 14, where adjusting the flow through the recirculation tube includes increasing flow through the recirculation tube. ### Claim 16 (depends on 14) The method of claim 14, where adjusting the flow through the recirculation tube includes decreasing flow through the recirculation tube. ### Claim 17 (depends on 14) The method of claim 14, where the flow is adjusted via adjusting an amount of time that a vapor blocking valve is held closed while the fuel tank is being filled. ### Claim 18 (depends on 14) The method of claim 14, further comprising holding open a canister vent valve while the fuel tank is being filled.