The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 14, 1994
Filed:
Mar. 04, 1993
Naoyuki Kamiya, Kariya, JP;
Toshifumi Hayami, Kariya, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A system for exactly detecting any unstable state in which disturbance is caused on the output value of a thermal air flowmeter for measuring intake air flow rate, thereby preventing or promptly suppressing the generation of undesirable states such as a variation in the air-fuel ratio or rough idling. The system has an upstream intake air temperature sensor for detecting the temperature of the intake air before entering an air cleaner element, the above-mentioned thermal air flowmeter, and a downstream air temperature sensor for detecting the temperature of the intake air after passing the thermal air flowmeter. The system determines that the air flow rate output of the thermal air flowmeter is unstable, when the difference between the air temperature values detected by the upstream and downstream intake air temperature sensors exceeds a predetermined value, and executes a control process which has been determined to cope with such an unstable state. Whether an unstable state exists or not may be determined from the amount of variation of the output value from the thermal air flowmeter.