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:
Mar. 18, 2008
Filed:
Mar. 12, 2007
Hajime Miura, Tama, JP;
Hajime Miura, Tama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
An internal combustion engine control apparatus is provided with a hydraulically operated variable valve operating mechanism for varying the valve timing of air intake valves, and a water temperature sensor for sensing engine coolant temperature to estimate the degree of engine warm-up. The valve operating mechanism is controlled to switch the valve timing from the warm-up idle valve timing with a high idling speed to the post-warm-up idle valve timing with a slower idling speed as the engine temperature approaches the warm-up temperature threshold. The switch in valve timings starts before an engine rotational speed falls below a rotational speed threshold lying between the high idling speed during the warm-up idling and the post-warm-up idling speed during the post-warm-up idling such that a sufficient hydraulic pressure switch the valve timing with a specific degree of responsiveness is attained when the engine rotational speed is at or above the rotational speed threshold.