# US 2014/0196685 A1 · Methods for reducing raw particulate engine emissions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196685 A1 - Document ID: US20140196685A1 - Status: Published application - Kind: A1 - Application number: 14/151,628 - Filed: 2014-01-09 - Published: 2014-07-17 - Earliest claimed: 2013-01-11 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Helmut Hans Ruhland; Georg Louven - Web page: https://patentgrep.com/patent/US20140196685A1 ## CPC - F02B 17/005: {having direct injection in the combustion chamber} - F02D 41/062: {for starting (F02D41/061 takes precedence)} - F02D 41/3023: {a mode being the stratified charge spark-ignited mode} - F02D 41/3076: {with special conditions for selecting a mode of combustion, e.g. for starting, for diagnosing} - F02D 41/064: {at cold start (F02D41/067 takes precedence)} - F02D 41/065: {at hot start or restart (F02D41/067 takes precedence)} - F02D 41/401: {Controlling injection timing (F02D41/402 takes precedence)} - F02D 41/402: {Multiple injections} - F02D 2200/0602: Fuel pressure - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - 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) ## Abstract The methods described allow for reducing particulate emissions from a direction injection engine during a starting phase, while also maintaining the engine start phase within a predetermined threshold. In one particular example, the methods comprise adjusting at least one of a fuel release pressure threshold and enrichment factor based on an engine condition; activating a starting device to rotate a crankshaft coupled to an engine cylinder without injecting any fuel; supplying fuel to the cylinder based on the enrichment factor only when a fuel pressure exceeds the fuel release pressure threshold; and stratifying a cylinder charge while adjusting a fuel injection within a compression phase and/or expansion phase of the engine. In this way, an amount of fuel injected may be evaporated in the combustion chamber while preventing a combustion wall wetting, which allows for reduced particulate emissions, particularly at reduced temperatures. ## Claims ### Claim 1 A method for reducing particulate emissions from a direct injection applied-ignition engine during a starting phase, comprising: adjusting at least one of a fuel release pressure threshold and enrichment factor based on one or more engine conditions; activating a starting device to rotate a crankshaft coupled to an engine cylinder without injecting any fuel; supplying fuel to the cylinder based on the enrichment factor only when a fuel pressure exceeds the fuel release pressure threshold; and stratifying a cylinder charge while adjusting at least one fuel injection within one of a compression phase and expansion phase of the engine. ### Claim 2 (depends on 1) The method of claim 1, wherein the at least one adjusted injection is performed close to ignition top dead center, and wherein the at least one injection is initiated in a crank angle range defined by at least one of: 125° before ignition top dead center and 75° after ignition top dead center; 90° before ignition top dead center and 45° after ignition top dead center; and 60° before ignition top dead center and 15° after ignition top dead center. ### Claim 3 (depends on 2) The method of claim 2, wherein the at least one adjusted injection is initiated during the compression phase. ### Claim 4 (depends on 2) The method of claim 2, wherein the at least one adjusted injection is initiated in the expansion phase. ### Claim 5 (depends on 1) The method of claim 1, wherein the fuel release pressure threshold includes a pressure threshold from the group consisting of 30 bar, 50 bar, and 75 bar. ### Claim 6 (depends on 1) The method of claim 1, wherein the engine is operated during the starting phase with an enrichment factor that falls below an enrichment threshold, and wherein the enrichment factor is defined by a ratio of an actually supplied fuel mass to a fuel mass required for stoichiometric combustion, the enrichment threshold being selected from a group consisting of 3, 1.5, 0.8, 0.6, and 0.4. ### Claim 7 (depends on 1) The method of claim 1, wherein the fuel release pressure threshold is reduced at lower engine temperatures. ### Claim 8 (depends on 7) The method of claim 7, further including advancing at least one of a fuel injection and spark timing based on the reduced fuel release pressure threshold. ### Claim 9 (depends on 1) The method of claim 1, wherein the fuel release pressure threshold is increased responsive to higher engine temperatures. ### Claim 10 (depends on 9) The method of claim 9, further including retarding at least one of a fuel injection and spark timing based on the increased fuel release pressure threshold. ### Claim 11 (depends on 1) The method of claim 1, wherein a pilot injection is carried out during an intake phase. ### Claim 12 A method for starting an engine from rest, comprising: only injecting fuel to a rotating engine after fuel pressure reaches a threshold; adjusting an air-fuel ratio produced by the injected fuel in the engine, the air-fuel ratio enleaned as the threshold is reduced; and spark-igniting the injected fuel in a stratified mixture. ### Claim 13 (depends on 12) The method of claim 12, further comprising injecting fuel within a window defined by a crank angle that falls within the range of 125° before ignition top dead center and 75° after ignition top dead center. ### Claim 14 (depends on 12) The method of claim 12, further comprising enriching the air-fuel ratio as the threshold is increased. ### Claim 15 (depends on 13) The method of claim 13, wherein starting the engine from rest includes performing an engine cold start, the engine cold start being indicated by an engine temperature that coincides with an ambient temperature. ### Claim 16 (depends on 15) The method of claim 15, further comprising setting the threshold based on one or more engine conditions, and adjusting the air-fuel ratio responsive to the threshold, the method further including decreasing the threshold to decrease a time for the fuel pressure to reach the threshold while enleaning the air-fuel ratio, and increasing the threshold to increase the time for the fuel pressure to reach the threshold while enriching the air-fuel ratio. ### Claim 17 A method for regulating an engine start phase, comprising: activating a starting device to rotate a crankshaft coupled to an engine cylinder while injecting no fuel to build up a fuel pressure; supplying fuel to the cylinder only when a fuel pressure exceeds a fuel release pressure threshold; and stratifying a cylinder charge while adjusting a fuel injection within an injection window that straddles a compression phase and expansion phase of the engine. ### Claim 18 (depends on 17) The method of claim 17, wherein the fuel release pressure threshold is reduced in response to lower temperatures and increased in response to higher temperatures. ### Claim 19 (depends on 18) The method of claim 18, wherein an enrichment factor defined by a ratio of an actual fuel mass supplied to a fuel mass required for stoichiometric combustion is adjusted to adjust an engine ramp up time. ### Claim 20 (depends on 19) The method of claim 19, wherein the injection window comprises a crank angle falling within the range of 125° before ignition top dead center and 75° after ignition top dead center.