# US 10,309,335 B2 · Fuel-supply system for an internal combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,335 B2 - Document ID: US10309335B2 - Status: Granted - Kind: B2 - Application number: 15/119,211 - Filed: 2015-08-17 - Published: 2017-07-27 - Granted: 2019-06-04 - Earliest claimed: 2014-10-14 - Assignees: Continental Automotive GmbH - Applicants: Continental Automotive GmbH - Inventors: Christoph Klesse; Thomas Riedel; Hans Riepl; Tobias Ritsch; Michael Wirkowski - Web page: https://patentgrep.com/patent/US10309335B2 ## CPC - F02D 41/3845: {by controlling the flow into the common rail, e.g. the amount of fuel pumped} - F02D 41/042: {for stopping the engine} - F02D 41/3863: {by controlling the flow out of the common rail, e.g. using pressure relief valves} - F02D 2250/02: Fuel evaporation in fuel rails, e.g. in common rails - F02M 63/0225: {Fuel-injection apparatus having a common rail feeding several injectors (F02M63/0003 takes precedence); Means for varying pressure in common rails; Pumps feeding common rails} - 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 The present invention relates to a method for operating a fuel supply system for an internal combustion engine, and to a corresponding device. The fuel supply system of an internal combustion engine may include: an outlet of a high-pressure pump coupled to a pressure-limiting valve and a high-pressure fluid accumulator. The method may include, when the internal combustion engine is set into a deactivated state, actuating the high-pressure pump such that, at the outlet side of the high-pressure pump, a pressure is increased such that the pressure-limiting valve is opened. ## Claims ### Claim 1 A method for operating a fuel supply system of an internal combustion engine, wherein the fuel supply system includes a pump having an outlet coupled to a high-pressure region including a fluid accumulator, wherein a normal operating pressure of the high-pressure region is between 200 bar and 350 bar, and a pressure-limiting valve having an inlet coupled to the high-pressure region including the fluid accumulator, the method comprising: when the internal combustion engine is set into a deactivated state, actuating the pump such that, at the outlet side of the pump, a pressure is increased in the high-pressure region including the fluid accumulator to a sufficient extent that the pressure-limiting valve is opened by the pressure in the high-pressure region acting on the inlet of the pressure-limiting valve; and monitoring a pressure at the outlet of the pump and ceasing actuation of the pump when the pressure exceeds a predefined opening threshold of the pressure-limiting valve; wherein the pressure limiting valve has an opening pressure less than 90 bar above the normal operating pressure of the high-pressure region and a closure threshold between 50 bar and 150 bar. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein the pressure-limiting valve comprises a direct-acting safety valve. ### Claim 3 (depends on 1) The method as claimed claim 1, wherein the pressure-limiting valve connects the outlet of the pump to a low-pressure region of the fuel supply system at the inlet side of the pump. ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein the pressure-limiting valve connects the outlet side of the high-pressure pump to a stroke chamber of the pump. ### Claim 5 (depends on 1) The method as claimed in claim 1, wherein a predefined closure threshold of the pressure-limiting valve is between 90 bar and 150 bar. ### Claim 6 (depends on 1) The method as claimed in claim 1, wherein the fuel supply system includes a sensor generating a measurement signal representative of the pressure at the outlet side of the pump. ### Claim 7 A fuel supply system of an internal combustion engine, the fuel supply system comprising: a pump having an outlet coupled to a high-pressure region with a normal operating pressure in the high-pressure region between 200 bar and 350 bar; a fluid accumulator arranged in the high-pressure region coupled to the outlet of the pump; a pressure-limiting valve having an inlet coupled to an outlet of the pump and coupled to the high-pressure region including the fluid accumulator; a sensor measuring a pressure at the outlet of the pump; and wherein actuation of the pump continues after the internal combustion engine has been deactivated until the sensor measures a pressure at the outlet side of the pump exceeding a predetermined opening value of the pressure-limiting valve; wherein the pressure limiting valve has an opening pressure less than 90 bar above the normal operating pressure of the high-pressure region and a closure threshold of between 50bar and 150 bar. ### Claim 8 (depends on 7) The fuel system as claimed in claim 7, wherein the pressure-limiting valve comprises a direct-acting safety valve. ### Claim 9 (depends on 7) The fuel system as claimed in claim 7, wherein the pressure-limiting valve connects the outlet of the pump to a relatively lower pressure region of the fuel supply system at the inlet side of the pump. ### Claim 10 (depends on 7) The fuel system as claimed in claim 7, wherein the pressure-limiting valve connects the outlet side of the high-pressure pump to a stroke chamber of the pump. ### Claim 11 (depends on 7) The fuel system as claimed in claim 7, wherein a predefined closure threshold of the pressure-limiting valve is between 90 bar and 150 bar. ### Claim 12 (depends on 7) The fuel system as claimed in claim 7, wherein actuation of the pump is ended based at least in part on the measurement signal of the sensor.