Title:
FUNCTION DIAGNOSIS DEVICE FOR VARIABLE VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINE
Document Type and Number:
Japanese Patent JP2943042
Kind Code:
B2
Abstract:
PURPOSE: To more accurately diagnose the function of a variable valve mechanism by extracting the strength of a frequency constituent for seating sound generated when-each suction valve and each exhaust valve are closed, comparing actual valve closing timing with valve closing timing by a control command based on the aforesaid strength, and thereby perforing diagnosis.
CONSTITUTION: A control unit 102 allows its frequency detecting section 201 to detect the frequency constituent and strength of the detected signal of an oscillation sensor 105. Based on a REF signal outputted from a cam sensor 106 and a POS signal outputted from an angle sensor 108, the vicinity of valve closing timing of a suction and an exhaust valve is set at the time of change- over between a high speed cam and a low speed cam, so that valve window pulses are thereby outputted by a valve closing timing detecting section 202. A built-in microcomputer diagnoses the function of a variable valve mechanism 101 based on a valve closing window pulse outputted from-the valve closing timing detecting section 202, and the frequency constituent and its strength of the detected signal of the oscillation sensor 105 detected by the frequency detecting section 201.
Inventors:
WATANABE SATORU
Application Number:
JP2984794A
Publication Date:
August 30, 1999
Filing Date:
February 28, 1994
Export Citation:
Assignee:
YUNISHIA JETSUKUSU KK
International Classes:
F02B77/08; F01L1/46; F01L13/00; F01L25/00; (IPC1-7): F01L13/00; F01L1/46; F02B77/08
Domestic Patent References:
| JP3172516A | ||||
| JP2275046A | ||||
| JP4112908A | ||||
| JP319447U |
Attorney, Agent or Firm:
Fumio Sasashima