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:
Jan. 20, 2004
Filed:
Mar. 12, 2003
Kazumi Nakano, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
In a case where no malfunction occurs in a water temperature control valve the temperature of the pump water is controlled to accurately follow a target water temperature. In contrast, in a case where the rotational opening degree of the water temperature control valve is accidentally fixed, the pump water temperature can no longer follow the target water temperature. In this instance, a control water temperature error between the target water temperature and the pump water temperature is calculated. When the control water temperature error is greater than a certain error range, a counter is incremented, and a malfunction judgment flag is set when the value of the counter exceeds a certain judgment threshold value at another time. Thereby, the temperature of the cooling water for the engine is feedback controlled while malfunction of the water temperature control valve can be accurately detected.