# US 5,701,868 A · Method and apparatus for controlling the ignition timing of 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 5,701,868 A - Document ID: US5701868A - Status: Granted - Kind: A - Application number: 08/783,291 - Filed: 1997-01-10 - Granted: 1997-12-30 - Earliest claimed: 1994-10-20 - Assignees: Unisia Jecs Corporation - Inventors: Naoki Tomisawa - Web page: https://patentgrep.com/patent/US5701868A ## CPC - 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 19/0634: {Determining a density, viscosity, composition or concentration (F02D19/087 takes precedence)} - F02D 19/0636: {by estimation, i.e. without using direct measurements of a corresponding sensor} - F02D 41/024: {to increase temperature of the exhaust gas treating apparatus} - F02D 41/0255: {to accelerate the warming-up of the exhaust gas treating apparatus at engine start} - F02P 5/1506: {with particular means during starting} - F02D 19/0649: {Liquid fuels having different boiling temperatures, volatilities, densities, viscosities, cetane or octane numbers} - F02D 2200/0611: Fuel type, fuel composition or fuel quality - F02P 5/045: {combined with electronic control of other engine functions, e.g. fuel injection (in general F02D37/02)} - Y02T 10/12: Improving ICE efficiencies - 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) - F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract The heavy/light grade of fuel supplied to an internal combustion engine is detected, for example with a sensor or by detecting fluctuations in combustion pressure, and a retard angle correction amount for control of an ignition timing retard angle for activating an exhaust gas purification catalytic converter during a predetermined interval after engine start-up, is set based on the detected properties of the fuel. The time required for activating the exhaust gas purification catalytic converter can thus be shortened by retarding the ignition timing, corresponding to the heavy/light grade of the fuel, to increase the exhaust temperature while maintaining combustion stability. ## Claims ### Claim 1 A method of controlling an ignition timing of an internal combustion engine, including the steps of: detecting a property of a fuel supplied to the internal combustion engine incorporating an exhaust gas purification catalytic converter in an exhaust passage and generating a corresponding first signal; determining a retard angle setting amount corresponding to the first signal; controlling an ignition device to set an ignition timing retard angle of the engine, during a predetermined interval after engine start-up, using a retard angle correction amount selected in correspondence with the determined retard angle setting amount; adjusting the retard angle correction amount to a progressively smaller value the heavier the detected property of the fuel, and to a progressively larger value the lighter the detected property of the fuel, and setting the retard angle correction amount to a level at which there is an increase in hydrocarbon amount generation in the exhaust gas; to thereby accelerate catalytic converter activity. ### Claim 2 (depends on 1) The method according to claim 1, wherein: the detecting of the property of fuel is based on surge torque at steady operating conditions. ### Claim 3 (depends on 1) The method according to claim 1, wherein: said fuel property detection is carried out by a sensor installed in a fuel line of the engine. ### Claim 4 Apparatus for controlling an ignition timing of an internal combustion engine provided with an exhaust gas purifying catalytic converter, comprising: means for detecting a selected property of a fuel supplied to the engine and for generating a corresponding first signal; means for determining a retard angle setting amount for the engine in correspondence with the first signal; means for controlling an ignition device to set an ignition timing retard angle of the engine, during a predetermined interval after engine start-up, using a retard angle correction amount selected in correspondence with the determined retard angle setting correction amount; means for adjusting the retard angle correction amount to a progressively smaller value the heavier the detected property of the fuel and to a progressively larger value the lighter the detected property of the fuel; and means for setting the retard angle correction amount to a level at which there is an increase in hydrocarbon amount in the exhaust gas to obtain an increase in catalytic converter activity. ### Claim 5 (depends on 4) The apparatus according to claim 4, wherein: the detecting means detects the selected property of the fuel based on surge torque at steady operating conditions. ### Claim 6 (depends on 4) The apparatus according to claim 4, wherein: the detecting means is a sensor installed in a fuel line of the engine.