Internal combustion engine

• US 6,338,245 B1
• Filed: 09/11/2000
• Issued: 01/15/2002
• Est. Priority Date: 09/17/1999
• Status: Expired due to Fees

• Current Assignee: HINO Motors Limited (Toyota Motor Corporation)
• Original Assignee: HINO Motors Limited (Toyota Motor Corporation)
• Inventors: Yokota, Haruyuki, Kakegawa, Toshiaki, Shimoda, Masatoshi
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): TRAN, DIEM T
• Application Number:
  US09/659,736
• Time in Patent Office: 491 Days
• Field of Search: 602/78, 602/80, 602/85, 602/98, 603/00, 602/97, 603/11, 603/01, 123/568.21
• US Class Current: 60/285
• CPC Class Codes: F01N 3/021 by means of filters
• CPC Class Codes: F02B 1/12 with compression ignition with fuel-air charge ignited by compression ignition of an additional fuel F02B7/00
• CPC Class Codes: F02B 29/0425 Air cooled heat exchangers
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02D 13/0234 changing the valve timing only
• CPC Class Codes: F02D 13/0261 Controlling the valve overlap
• CPC Class Codes: F02D 15/04 by alteration of volume of compression space without changing piston stroke
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 21/08 the other gas being the exhaust gas of engine
• CPC Class Codes: F02D 41/3035 a mode being the premixed charge compression-ignition mode
• CPC Class Codes: F02D 41/3076 with special conditions for selecting a mode of combustion, e.g. for starting, for diagnosing
• CPC Class Codes: F02D 41/38 of the high pressure type
• CPC Class Codes: F02M 26/06 Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor
• CPC Class Codes: F02M 26/15 in relation to engine exhaust purifying apparatus
• 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: F02M 26/47 the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A diesel engine includes a turbocharger, an intercooler, a particulate filtering unit, and an EGR cooler. EGR ratio of intake air, injection timing of an injection nozzle, and excess air ratio to fuel are controlled depending upon engine-operating load. Lean premixed compression ignition is performed at low engine load; low temperature combustion at low excess air ratio with high EGR ratio is performed at medium engine load; and normal EGR combustion is performed at high engine load.

Claims

1. An internal combustion engine comprising means for decreasing combustion temperature and means for increasing ignition delay, both of said means being used at low to medium engine load such that combustion of fuel in the engine is at a temperature lower than that at which NO_x is produced and at an equivalent ratio lower than that at which soot is produced, said means for decreasing combustion temperature being used at medium to high engine load such that combustion of the fuel in the engine is at a temperature lower than that at which NO_x or soot is produced.

2. An internal combustion engine as set forth in claim 1 further comprising an exhaust gas recirculation passage for communication of an exhaust conduit downstream of a turbine of a turbocharger with an intake conduit upstream of a compressor of the turbocharger and means for removing particulate matter provided on a portion of the exhaust conduit upstream of a connection of said exhaust conduit with the exhaust gas recirculation passage.

3. An internal combustion engine as set forth in claim 1 wherein the means for increasing ignition delay comprises means for controlling timing of fuel injection to set earlier timing for fuel injection.

4. An internal combustion engine as set forth in claim 2 wherein the means for decreasing combustion temperature comprises means for recirculating exhaust gas to the engine via the exhaust gas recirculation passage.

5. An internal combustion engine as set forth in claim 2 wherein circulation ratio of the exhaust gas to be circulated to the engine via the exhaust gas recirculation passage is set to more than about 40% at low to medium engine load, to more than about 50% at medium to high engine load and to less than about 50% at high engine load.

6. An internal combustion engine as set forth in claim 2 further comprising means for cooling the exhaust gas in the exhaust gas recirculation passage.

7. An internal combustion engine as set forth in claim 1 further comprising control means for adjusting timing for closing an intake valve for intake to the engine, said timing for closing the intake valve being retarded by said control means as the engine load is increased.