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:
Dec. 28, 1999
Filed:
Sep. 03, 1997
Eiichi Tomioka, Saitama-ken, JP;
Jidosha Kiki Co., Ltd., Tokyo, JP;
Abstract
A method is provided for controlling an electric power pump type power steering system. In this method, there are provided a brushless motor (1) rotating, when a current is fed to coils, for driving a hydraulic pump of an automotive vehicle, thereby obtaining an assist power; a plurality of upper transistors (Q1) connected to the coils of the brushless motor with a control voltage being higher than a drive voltage of the brushless motor; a plurality of lower transistors (Q2) connected to a connection point between the coils of the brushless motor and the plurality of transistors and connected to each other; a controller (6) for selectively turning on one transistor out of the plurality of upper transistors in order and repeating an operation of selectively turning on one transistor other than the transistor connected to the upper transistor which has been turned on, out of the plurality of the lower transistors, thereby feeding the current to the coils for respective phases of the brushless motor; and a capacitor (C1), connected at one terminal to a power source and at the other terminal to each connection point between the upper and lower transistors and the coils, for accumulating a drive energy therein. When the upper transistor is turned off, the other terminal of the capacitor is set at a ground potential so that the drive energy of the upper transistor is accumulated in the capacitor.