Title:
OXYGEN CONCENTRATION DETECTOR
Document Type and Number:
Japanese Patent JP3680445
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To conduct current detection exactly by suppressing sensor current appropriately in any other range than an oxygen concentration detection range.
SOLUTION: An A/F sensor (limiting current type air-fuel ratio sensor) 30 outputs a linear A/F (air-fuel ratio) detection signal in proportion to an oxygen concentration in exhaust gas from an engine 10 according to applied voltage commanded from a microcomputer 20. The microcomputer 20 controls the applied voltage into the A/F sensor 30 so as to limit sensor current to a prescribed value in the area out of air-fuel detection range (out of oxygen concentration detection range). The applied voltage is controlled on a V-I coordinate by prescribed positive characteristics in the air-fuel detection range, and the applied voltage is controlled by characteristics different from the above positive characteristics out of air-fuel ratio detection range. On the rich side out of the air-fuel ratio detection range, the applied voltage is controlled so as to approach the maximum value (0.9V) of electromotive force of the A/F sensor 30. On the lean side out of the air-fuel ratio detection range, the applied voltage is controlled so as to approach the minimum value (0V) of the electromotive force of the sensor 30.
Inventors:
Masayuki Takami
Mizoguchi morning road
Tetsushi Haseda
Kazuhiro Okazaki
Mizoguchi morning road
Tetsushi Haseda
Kazuhiro Okazaki
Application Number:
JP26714896A
Publication Date:
August 10, 2005
Filing Date:
October 08, 1996
Export Citation:
Assignee:
株式会社デンソー
International Classes:
G01N27/41; G01N27/406; G01N27/416; (IPC1-7): G01N27/41
Domestic Patent References:
| JP2045751A | ||||
| JP61180131A | ||||
| JP566216A |
Attorney, Agent or Firm:
Hironobu Onda