# US 11,028,785 B2 · Control device for internal combustion engine and control method for 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 11,028,785 B2 - Document ID: US11028785B2 - Status: Granted - Kind: B2 - Application number: 16/316,820 - Filed: 2017-06-29 - Published: 2019-07-25 - Granted: 2021-06-08 - Earliest claimed: 2016-07-14 - Assignees: Yanmar Power Technology Co., Ltd. - Applicants: Yanmar Co., Ltd. - Inventors: Go Asai - Web page: https://patentgrep.com/patent/US11028785B2 ## CPC - F02D 19/0671: {Means to generate or modify a fuel, e.g. reformers, electrolytic cells or membranes} - F02B 43/04: for improving efficiency of combustion - F02B 43/12: Methods of operating - F02D 19/0607: {to adjust the fuel mass or volume flow} - F02D 19/0615: {being initiated by automatic means, e.g. based on engine or vehicle operating conditions} - F02D 19/0628: {Determining the fuel pressure, temperature or flow, the fuel tank fill level or a valve position} - F02D 19/0644: {the gaseous fuel being hydrogen, ammonia or carbon monoxide} - F02D 19/08: simultaneously using pluralities of fuels (F02D19/12 takes precedence) - F02D 19/081: {Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other} - F02D 19/10: peculiar to compression-ignition engines in which the main fuel is gaseous - F02D 19/105: {operating in a special mode, e.g. in a liquid fuel only mode for starting} - F02D 41/0025: {Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures} - F02D 41/0027: {the fuel being gaseous (non-electrical control F02D19/02)} - F02D 41/1475: {Regulating the air fuel ratio at a value other than stoichiometry} - F02D 41/18: by measuring intake air flow - F02D 41/403: {with pilot injections} - F02M 25/00: Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture (adding secondary air to fuel-air mixture F02M23/00; adding exhaust gases F02M26/00; fuel-injection apparatus operating simultaneously on two or more fuels or on a liquid fuel and another liquid F02M43/00) - F02M 26/36: with means for adding fluids other than exhaust gas to the recirculation passage; with reformers - F02D 41/042: {for stopping the engine} - F02D 41/062: {for starting (F02D41/061 takes precedence)} - F02D 2200/0606: Fuel temperature - Y02T 10/30: Use of alternative fuels, e.g. biofuels - Y02T 10/40: Engine management systems - 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) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An internal combustion engine in which a fuel reforming operation in a fuel reformation cylinder is not executed when a gas temperature of a fuel reformation chamber at a time point when a piston in the fuel reformation cylinder reaches a compression top dead point is estimated to fall short of a reforming operation allowable lower limit gas temperature set based on a lower limit value of a reforming reaction enabling temperature. For example, fuel is supplied from an injector so that an equivalence ratio in the fuel reformation chamber is less than 1. Alternatively, the fuel supply from an injector is stopped. This way, a supply of non-reformed fuel from the fuel reformation cylinder to an output cylinder can be avoided, and knocking in the output cylinder can be avoided. ## Claims ### Claim 1 A control device for an internal combustion engine including a fuel reformation cylinder and an output cylinder to which reformed fuel generated in the fuel reforming cylinder is supplied, the output cylinder being configured to yield an engine power by combusting the reformed fuel, the control device comprising: a reforming operation control unit configured not to execute a fuel reforming operation in the fuel reformation cylinder, when a gas temperature in the fuel reformation cylinder at a time point when a periodically changing gas temperature in the fuel reformation cylinder reaches its highest temperature is estimated to fall short of a reforming operation allowable lower limit gas temperature set based on a lower limit value of a reforming reaction enabling temperature; and wherein: the reforming operation allowable lower limit gas temperature is set so as to be higher with an increase in an air fuel mixture equivalence ratio in the fuel reformation cylinder; the fuel reformation cylinder is structured as a reciprocation type cylinder; and the gas temperature reaches its highest temperature when a piston in the fuel reformation cylinder reaches a compression top dead point. ### Claim 2 (depends on 1) The control device according to claim 1, wherein the reforming operation control unit is configured to: determine the air fuel mixture equivalence ratio in the fuel reformation cylinder; and calculate the reforming operation allowable lower limit gas temperature based on the air fuel mixture equivalence ratio. ### Claim 3 (depends on 2) The control device according to claim 2, wherein: the reforming operation allowable lower limit gas temperature is corrected based on a type of fuel to be supplied to the fuel reformation cylinder. ### Claim 4 (depends on 1) The control device according to claim 1, wherein: the fuel reforming operation in the fuel reformation cylinder is not executed during a start mode operation executed at an early start-up stage of the internal combustion engine and during a stop mode operation executed at a time of stopping of the internal combustion engine, irrespective of the gas temperature at the time point when the gas temperature in the fuel reformation cylinder reaches its highest temperature. ### Claim 5 (depends on 1) The control device according to claim 1, wherein: when the fuel reforming operation in the fuel reformation cylinder is not executed, an amount of fuel within a range that allows fuel combustion in the fuel reformation cylinder and that makes the air fuel mixture equivalence ratio in the fuel reformation cylinder less than 1 is supplied to the fuel reformation cylinder. ### Claim 6 (depends on 1) The control device according to claim 1, wherein: when the fuel reforming operation in the fuel reformation cylinder is not executed, a fuel supply to the fuel reformation cylinder is stopped, and an amount of fuel within a range that allows fuel combustion in the output cylinder is supplied to the output cylinder. ### Claim 7 A control method for an internal combustion engine including a fuel reformation cylinder and an output cylinder to which reformed fuel generated in the fuel reforming cylinder is supplied, the output cylinder being configured to yield an engine power by combusting the reformed fuel, wherein: a fuel reforming operation in the fuel reformation cylinder is not executed, when a gas temperature in the fuel reformation cylinder, at a time point when a periodically changing gas temperature in the fuel reformation cylinder reaches its highest temperature, is estimated to fall short of a reforming operation allowable lower limit gas temperature set based on a lower limit value of a reforming reaction enabling temperature; the reforming operation allowable lower limit gas temperature is set so as to be higher with an increase in an air fuel mixture equivalence ratio in the fuel reformation cylinder; the fuel reformation cylinder is structured as a reciprocation type cylinder; and the gas temperature reaches its highest temperature when a piston in the fuel reformation cylinder reaches a compression top dead point. ### Claim 8 (depends on 7) The method of claim 7, further comprising determining the air fuel mixture equivalence ratio and calculating the reforming operation allowable lower limit gas temperature based on the equivalence ratio. ### Claim 9 (depends on 7) The method of claim 7, further comprising executing the fuel reforming operation in the fuel reformation cylinder when the gas temperature, at the time point when the periodically changing gas temperature in the fuel reformation cylinder reaches its highest temperature, is estimated to exceed the reforming operation allowable lower limit gas temperature. ### Claim 10 (depends on 7) The method of claim 7, further comprising injecting a first amount of fuel into the fuel reformation cylinder based on not executing the fuel reforming operation.