Method for operating an internal combustion engine, and motor vehicle

• US 6,789,512 B2
• Filed: 11/08/2002
• Issued: 09/14/2004
• Est. Priority Date: 11/10/2001
• Status: Expired due to Fees

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: DaimlerChrysler AG (Mercedes-Benz Group AG)
• Inventors: Klingebiel, Matthias, Welte, Lothar, Sass, Helko, Duvinage, Frank, Pfaff, Ruediger
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US10/291,855
• Publication Number:
  US 20030089319A1
• Time in Patent Office: 676 Days
• Field of Search: 123/41.1, 123/41.12, 123/41.44, 123/41.31, 123/568.12, 123/568.21, 123/568.27, 123/550, 123/552, 123/41.05, 123/27.R, 123/563
• US Class Current: 123/41.05
• CPC Class Codes: B60H 1/02 the heat being derived from the propulsion plant B60H1/00492 takes precedence
• CPC Class Codes: F01P 2025/08 Temperature
• CPC Class Codes: F01P 2025/31 Cylinder temperature
• CPC Class Codes: F01P 2025/32 Engine outcoming fluid temperature
• CPC Class Codes: F01P 2025/33 Cylinder head temperature
• CPC Class Codes: F01P 2025/40 Oil temperature
• CPC Class Codes: F01P 2037/02 starting
• CPC Class Codes: F01P 2060/02 Intercooler
• CPC Class Codes: F01P 2060/04 Lubricant cooler
• CPC Class Codes: F01P 2060/08 Cabin heater
• CPC Class Codes: F01P 3/20 Cooling circuits not specific to a single part of engine or machine F01P3/22 takes precedence
• CPC Class Codes: F01P 7/10 by throttling amount of air flowing through liquid-to-air heat exchangers
• CPC Class Codes: F01P 7/164 by varying pump speed
• CPC Class Codes: F01P 7/167 by adjusting the pre-set temperature according to engine parameters, e.g. engine load, engine speed
• CPC Class Codes: F02B 29/0443 Layout of the coolant or refrigerant circuit
• CPC Class Codes: F02D 2041/1422 Variable gain or coefficients
• CPC Class Codes: F02D 35/025 by determining temperatures inside the cylinder, e.g. combustion temperatures
• CPC Class Codes: F02D 41/0047 Controlling exhaust gas recirculation [EGR] temperature control with cooler in recirculation circuit F02M26/33
• CPC Class Codes: F02D 41/0055 Special engine operating conditions, e.g. for regeneration of exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/0065 Specific aspects of external EGR control constructional details of EGR system F02M26/00
• CPC Class Codes: F02D 41/068 : for warming-up
• CPC Class Codes: F02D 41/086 : taking into account the temperature of the engine
• CPC Class Codes: F02D 41/405 : with post injections
• CPC Class Codes: F02M 26/28 : with liquid-cooled heat exchangers
• CPC Class Codes: F02M 26/33 : controlling the temperature of the recirculated gases
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 : Engine management systems

Abstract

In a method for operating an internal combustion engine, and a motor vehicle to be heated by the engine coolant, wherein the internal combustion engine has a cooling circuit, a heating mode can be established in which operating parameters of the internal combustion engine, while satisfying required output set values, are set for the maximum possible introduction of heat into the coolant and the exhaust gas in order to reach or hold a desired coolant temperature.

Claims

1. A method for operating an internal combustion engine which has a coolant circuit and exhaust gas re-circulation, during warm-up by switching engine operation from a normal mode to a heating mode for rapidly reaching or holding a desired coolant temperature, wherein operating parameters of the internal combustion engine, while satisfying required output values, are set for the maximum possible introduction of heat into the coolant and/or the exhaust gas, said method comprising the step of setting an exhaust-gas re-circulation rate in an exhaust-gas re-circulation device of the internal combustion engine to a maximum possible value while maintaining predetermined limit values.

2. A method according to claim 1, wherein, in said heating mode, in order to increase a combustion-chamber surface temperature, combustion is temporally advanced with respect to the combustion in standard operation, while a maximum allowable combustion-chamber pressure is maintained.

3. A method according to claim 1, wherein, in said heating mode, the combustion is delayed with respect to the combustion during normal engine operation, while predetermined limits for a combustion-chamber surface temperature are maintained.

4. A method according to claim 1, wherein, in said heating mode, the engine idling speed is increased compared to standard operation, while the oil temperature and a the coolant temperature are monitored.

5. A method according to claim 1, wherein, in the heating mode, flow of coolant through the internal combustion engine is set to zero for a predetermined period of time after engine startup.

6. A method according to claim 1, wherein, in the heating mode, the coolant flow through the internal combustion engine is controlled as a function of the combustion-chamber surface temperature and the engine operating point.

7. A method according to claim 1, wherein, in the heating mode, a radiator shutter disposed in front of the radiator is closed.

8. A method according to claim 1, wherein, in said heating mode, an engine charging pressure of a supercharging device of the internal combustion engine is increased to increase the exhaust-gas re-circulation rate.

9. A method according to claim 8, wherein, in the heating mode, an air flow through a charge-air cooler of said supercharging device of the internal combustion engine is set to zero.

10. A method according to claim 1, wherein, in the heating mode, in order to shift the average combustion time with respect to standard operation, the injection quantities and/or injection times of a pre-injection, main injection and/or after-injection are changed.

11. A method according to claim 10, wherein, in the heating mode, at least one of the fuel injection pressure and the injection duration are increased in order to increase a fuel injection quantity.

12. A method according to claim 1, wherein with a control means for controlling the coolant temperature of the internal combustion engine, the combustion-chamber surface temperature and the oil temperature are monitored for maintaining them below a limit value.

13. A method according to claim 12, wherein in the control means, the coolant temperature at the coolant outlet of the internal combustion engine, the combustion-chamber surface temperature and the oil temperature are prioritized in that order.

14. A method according to claim 13, wherein the control means has at least one controller with a variable control characteristic.

15. A motor vehicle having an internal combustion engine and a heater installation for rapidly heating the interior of the vehicle, comprising means for monitoring variables which are characteristic of a heating state of the internal combustion engine and means for setting a heating mode of the internal combustion engine, in which operating parameters of the internal combustion engine, while satisfying required output set values, are set during a starting phase of the engine for a maximum possible introduction of heat into the coolant and the exhaust gas.

16. A motor vehicle according to claim 15, comprising an independently controllable coolant pump for controlling the flow of coolant independently of the engine speed.

17. A motor vehicle according to claim 15, wherein a bypass line is provided for bypassing a coolant radiator including a mixing valve, which can be controlled by means of a central control unit for setting the respective flows of coolant through the bypass line and the cooling system radiator.

18. A motor vehicle according to claim 15, wherein an exhaust-gas re-circulation cooler is provided in the cooling circuit.

19. A motor vehicle according to claim 18, wherein the exhaust-gas re-circulation and a heater are connected in a series arrangement in the cooling circuit.