Title:
TIRE AIR PRESSURE DETECTING DEVICE
Document Type and Number:
Japanese Patent JP3391482
Kind Code:
B2
Abstract:
PURPOSE: To prevent an erroneous judgment by detecting the signal containing the tire vibration frequency component at the time of a travel, extracting the resonance frequency component, comparing the signal level with the set value, and detecting the state of the air pressure based on the resonance frequency calculated from the selected signal.
CONSTITUTION: Tires 1a-1d are provided with wheel speed sensors constituted of pulsers 2a-2d and pickup coils 3a-3d, AC signals having frequencies corresponding to the revolving speeds of the tires 1a-1d are inputted to an ECU 4, and calculated results are displayed on a display section 5. The ECU 4 makes a frequency analysis on the wheel speed calculated front each input AC signal, extracts the signal of the resonance frequency component, and compares the magnitude of the signal level with a set value. The resonance frequency is calculated with only the signal in the prescribed range, and a warning is issued when the resonance frequency corresponding to the tire air pressure reduction warning pressure is obtained based on the result. Therefore, even if the signal level changes, no erroneous judgment is made.
Inventors:
Toshiharu Naito
Taguchi Health
Kenji Fujiwara
Taguchi Health
Kenji Fujiwara
Application Number:
JP29784392A
Publication Date:
March 31, 2003
Filing Date:
October 09, 1992
Export Citation:
Assignee:
株式会社デンソー
International Classes:
B60C23/02; G01L17/00; (IPC1-7): B60C23/02
Domestic Patent References:
| JP62149503A |
Other References:
【文献】「自動車技術ハンドブック」第1分冊 基礎・理論編、第1版、社団法人 自動車技術会 1990年12月1日 p264~288
Attorney, Agent or Firm:
Hirohiko Usui (1 outside)