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:
Apr. 04, 2000
Filed:
Mar. 02, 1998
Dipchand V Nishar, Boston, MA (US);
Thomas A Dollmeyer, Columbus, IN (US);
Cummins Engine Company, Inc., Columbus, IN (US);
Abstract
A system for controlling air flow to an engine cooling system includes a control computer responsive to a number of engine and/or engine accessory operating conditions, and to various engine operational states to control operation of an engine cooling device. The engine operational states are each a function of at least engine fueling commands and include a 'free energy' state corresponding to zero fueling, an 'absorbing additional torque' state corresponding to zero fueling and activation of either service brakes or engine brakes, and a 'needs additional torque' state corresponding to a rapid positive change in fueling, recent gear shifting to the lower gears of the transmission with fueling above a predefined level or a high rate of change in fueling rate. All other engine operational states are defined as a don't care state. The control computer is operable to control the engine cooling device as a function of the number of engine and/or engine accessory operating conditions and a current engine operating state, wherein examples of the engine and/or engine accessory operating conditions include engine coolant temperature, rate of change of engine coolant temperature, intake manifold air temperature and air conditioner refrigerant pressure. The engine cooling device is preferably a single speed, dual speed or variable speed engine cooling fan.