Title:
DETECTION APPARATUS FOR CONCENTRATION OF OXYGEN
Document Type and Number:
Japanese Patent JP3692847
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To acquire the relationship between the temperature of a heater and the resistance value of the heater, in a short time without installing a separate routine.
SOLUTION: An air/fuel ratio sensor 101, which is installed in the exhaust passage 6 of an engine 200, is provided. A heater 104 which heats the air/fuel ratio sensor is provided. A heater control means 100 which controls electric power supplied to the heater is provided. On the basis of the resistance value of the heater acquired in the specific operating state of the engine during the control of the electric power supplied to the heater by the feedback of the element impedance of the air-fuel ratio sensor performed after the activation of the air-fuel ratio sensor, the relationship between the temperature of the heater and the resistance value of the heater is acquired. When the relationship between the element temperature and the element impedance of the air-fuel ratio sensor is different from the same relationship at a time when the air-fuel ratio sensor is an initial product, the acquisition of the relationship between the temperature of the heater and the resistance value of the heater is inhibited.
Inventors:
Keiichiro Aoki
Application Number:
JP22169399A
Publication Date:
September 07, 2005
Filing Date:
August 04, 1999
Export Citation:
Assignee:
TOYOTA JIDOSHA KABUSHIKI KAISHA
International Classes:
G01N27/41; F02D41/14; F02D45/00; G01N27/409; (IPC1-7): G01N27/41; F02D41/14; F02D45/00; G01N27/409
Domestic Patent References:
| JP3019957U |
Attorney, Agent or Firm:
Takashi Ishida
Jun Tsuruta
Shigeru Tsuchiya
Masaya Nishiyama
Jun Tsuruta
Shigeru Tsuchiya
Masaya Nishiyama