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:
Jul. 01, 2008
Filed:
Dec. 22, 2004
Norikazu Matsuzaki, Mito, JP;
Norikazu Matsuzaki, Mito, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
To provide a four-wheel drive system which improves running performance of an automotive vehicle by inhibiting a driving torque from becoming insufficient upon occurrence of a slip. An R slip sensing means of a DC motor torque calculating means senses a slip due to a spin of rear wheels. When the rear wheel slip is sensed, an R slip DC-motor-torque correcting means corrects a torque of the rear wheels so that a driving force of the rear wheels is reduced and then increased. The R slip DC-motor-torque correcting means reduces a driving torque of the rear wheels to eliminate the slip and holds the reduced driving torque until the slip is eliminated, and then increases the driving torque to a value lower than a value which the driving torque has taken at the time of occurrence of the slip. The driving torque is increased to a predetermined limit value depending on the number of slips.