# US 7,406,937 B2 · Method for operating 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 7,406,937 B2 - Document ID: US7406937B2 - Status: Granted - Kind: B2 - Application number: 10/540,657 - Filed: 2003-06-24 - Published: 2006-09-14 - Granted: 2008-08-05 - Earliest claimed: 2002-12-23 - Assignees: Robert Bosch GmbH - Inventors: André-Francisco Casal Kulzer; Jochen Laubender; Udo Sieber - Web page: https://patentgrep.com/patent/US7406937B2 ## CPC - F02D 13/0215: {changing the valve timing only} - F02D 41/062: {for starting (F02D41/061 takes precedence)} - F02N 19/004: {Aiding engine start by using decompression means or variable valve actuation} - F02N 99/006: {Providing a combustible mixture inside the cylinder} - F02D 13/0207: {changing valve lift or valve lift and timing} - F02D 13/0238: {by shifting the phase, i.e. the opening periods of the valves are constant} - F02D 13/0249: {changing the valve timing only} - F02D 13/0265: {Negative valve overlap for temporarily storing residual gas in the cylinder} - F02D 2013/0292: {in the start-up phase, e.g. for warming-up cold engine or catalyst} - Y02T 10/12: Improving ICE efficiencies - 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) - F02N: STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A method for operating an internal combustion engine having at least one triggerable intake valve and at least one triggerable discharge valve, in which the internal combustion engine is directly started in a start-up operating mode and, following the start, is operated in at least one other operating mode. A starting discharge instant of a discharge valve of the internal combustion engine that is used during the start-up operating mode is retarded in time with respect to a standard discharge instant so as to improve the direct start-up characteristics of the internal combustion engine. In addition, to further improve the direct start-up characteristics, it is possible to retard a closing instant of an intake valve that is used during the start-up operating mode with respect to a standard closing instant. ## Claims ### Claim 1 A method for operating an internal combustion engine having at least one triggerable intake valve and at least one triggerable discharge valve, comprising: directly starting the internal combustion engine in a start-up operating mode in which the discharge valve discharges an exhaust gas of the internal combustion engine; and following the directly starting, operating the internal combustion engine in at least one additional operating mode; performing a retardation involving at least one of: time-retarding a starting discharge instant of the discharge valve with respect to a standard discharge instant used during the at least one additional operating mode, and time-retarding an opening instant and a closing instant of the intake valve with respect to a standard closing instant used during the at least one additional operating mode, the intake valve being used during the start-up operating mode for an aspiration of a fresh gas. ### Claim 2 (depends on 1) The method as recited in claim 1, wherein the retardation is implemented by adjusting at least one of a discharge camshaft that triggers the discharge valve and an intake camshaft that triggers the intake valve. ### Claim 3 (depends on 2) The method as recited in claim 2, further comprising: using a phase actuator in each case to adjust one of the intake camshaft and the discharge camshaft. ### Claim 4 (depends on 2) The method as recited in claim 2, further comprising: using a phase actuator for the simultaneous adjustment of the intake camshaft and the discharge camshaft. ### Claim 5 (depends on 2) The method as recited in claim 2, further comprising: using a valve-gear system influencing an opening time of one of the intake valve and the discharge valve to adjust one of the intake camshaft and the discharge camshaft. ### Claim 6 (depends on 2) The method as recited in claim 2, wherein at least one of the intake camshaft and the discharge camshaft is already adjusted during a deactivation of the internal combustion engine for a subsequent start in the start-up operating mode. ### Claim 7 (depends on 1) The method as recited in claim 1, wherein at least one of the intake valve and the discharge valve is triggered by a camshaft-free valve-gear system. ### Claim 8 (depends on 1) The method as recited in claim 1, wherein a valve lift of one of the intake valve and the discharge valve is varied. ### Claim 9 (depends on 1) The method as recited in claim 1, further comprising: decreasing the retardation in a stepwise manner with increasing rotational speed of the internal combustion engine. ### Claim 10 (depends on 1) The method as recited in claim 1, further comprising: deactivating the retardation once a predefinable minimum rotational speed of the internal combustion engine is exceeded. ### Claim 11 An internal combustion engine, comprising: at least one triggerable intake valve; at least one triggerable discharge valve that is directly started in a start-up operating mode and, following the start, is operated in at least one additional operating mode; and an arrangement for performing a retardation including at least one of: an arrangement for time-retarding a starting discharge instant of the discharge valve with respect to a standard discharge instant used during the at least one additional operating mode, and an arrangement for time-retarding an opening instant and a closing instant of the intake valve with respect to a standard closing instant used during the at least one additional operating mode, the intake valve being used during the start-up operating mode for an aspiration of a fresh gas. ### Claim 12 A control device for an internal combustion engine having at least one triggerable intake valve and at least one triggerable discharge valve that is directly started in a start-up operating mode and, following the start, is operated in at least one additional operating mode, comprising: an arrangement for performing a retardation including at least one of: an arrangement for time-retarding a starting discharge instant of the discharge valve with respect to a standard discharge instant used during the at least one additional operating mode, and an arrangement for time-retarding an opening instant and a closing instant of the intake valve with respect to a standard closing instant used during the at least one additional operating mode, the intake valve being used during the start-up operating mode for an aspiration of a fresh gas. ### Claim 13 A computer program for a control device for an internal combustion engine having at least one triggerable intake valve and at least one triggerable discharge valve that is directly started in a start-up operating mode and, following the start, is operated in at least one additional operating mode, comprising: instructions for performing a retardation including at least one of: instructions for time-retarding a starting discharge instant of the discharge valve with respect to a standard discharge instant used during the at least one additional operating mode, and instructions for time-retarding an opening instant and a closing instant of the intake valve with respect to a standard closing instant used during the at least one additional operating mode, the intake valve being used during the start-up operating mode for an aspiration of a fresh gas. ### Claim 14 (depends on 13) The computer program as recited in claim 13, wherein the computer program is stored on an electric memory medium. ### Claim 15 (depends on 14) The computer program as recited in claim 14, wherein: the electric memory medium includes one of a flash memory and a read-only memory.