(19)
(11) EP 1 245 809 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
10.11.2004 Bulletin 2004/46

(43) Date of publication A2:
02.10.2002 Bulletin 2002/40

(21) Application number: 02007155.1

(22) Date of filing: 28.03.2002
(51) International Patent Classification (IPC)7: F02D 31/00, F02D 41/16, F02D 41/12
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 29.03.2001 JP 2001095573

(71) Applicant: Denso Corporation
Kariya-city, Aichi-pref., 448-8661 (JP)

(72) Inventor:
  • Kudo, Toru
    Kariya-city, Aichi-pref., 448-8661 (JP)

(74) Representative: Leson, Thomas Johannes Alois, Dipl.-Ing. 
Tiedtke-Bühling-Kinne & Partner GbR, TBK-Patent, Bavariaring 4
80336 München
80336 München (DE)

   


(54) Method for controlling idling speed of internal combustion engine


(57) If the driver takes foot off the accelerator while the running condition of the vehicle, an engine speed decreases to a target engine speed for an idling condition. A corrective injection amount is calculated and added on a base injection amount when the engine speed is in a vicinity of the target engine speed (Neisc + ΔN2 ≤ Ne < Neisc + ΔN1). The corrective injection amount is calculated based on a decreasing speed dNe/dt of the Ne. The corrective amount is gradually increased by an affecting ratio coefficient Kdl so that 100 % of the corrective amount is fully effective when the engine speed Ne coincides with the target engine speed Neisc. As a result, it is possible to suppress a decreasing speed of the engine speed. It is possible to prevent the engine speed from an excessive drop with respect to the target engine speed. It is possible to approach the engine speed smoothly to the target engine speed.






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