Title:
CONTROL DEVICE FOR ENGINE
Document Type and Number:
Japanese Patent JP3510132
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To control the air-fuel ratio every cylinder by providing, on a control device, an air-fuel ratio calculating means for calculating the air-fuel ratio on the basis of the output signal of an air-fuel ratio sensor and a means for analyzing the value calculated by the air-fuel ratio calculating means to a frequency component within a prescribed range to estimate the air-fuel ratio every cylinder.
SOLUTION: An air flow sensor 2 detects the air quantity, a throttle 3 regulates the air quantity, and a crank angle sensor 15 outputs a signal every degree of the rotating angle of crank angle. The exhaust gas after combustion is discharged to an exhaust manifold 10 and released to the outside. An A/F sensor 12 is mounted in an exhaust collecting part to detect the oxygen concentration in the exhaust gas. For the air-fuel ratio estimated value every cylinder of an engine, a frequency analyzing means 52 analyses the air-fuel ratio RABF calculated by an air-fuel ratio arithmetic means 51 to estimate the air-fuel ratio every cylinder, and a correction item arithmetic means 54 calculates a correction item by the comparison with a target air-fuel ratio on the basis of the estimated air-fuel ratio every cylinder. According to this, the cycle internal fluctuation of air-fuel ratio can be suppressed.
Inventors:
Nakagawa, Shinji
Ishii, Toshio
Takaku, Yutaka
Osuga, Minoru
Ishii, Toshio
Takaku, Yutaka
Osuga, Minoru
Application Number:
JP1862399A
Publication Date:
March 22, 2004
Filing Date:
January 27, 1999
Export Citation:
Assignee:
HITACHI LTD
International Classes:
F02D45/00; F02D41/04; (IPC1-7): F02D41/04; F02D45/00
Attorney, Agent or Firm:
平木 祐輔