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:
Nov. 12, 2002
Filed:
Feb. 22, 1999
Tokiro Kogane, Nagano, JP;
Satoru Tokida, Nagano, JP;
Nissei Plastics Industrial Co., Ltd., Nagono-ken, JP;
Abstract
A method for operating a hydraulic drive apparatus in which flows of oil discharged from a plurality of hydraulic drive sources each using a hydraulic pump are merged in order to drive an actuator. At least in a pressure control mode, one of the hydraulic drive sources (main hydraulic drive source) is operated in a regular manner, and the other hydraulic drive source (auxiliary hydraulic drive source) is operated such that at A merge point where the oil flows merge, the pressure of oil from the auxiliary hydraulic drive source becomes lower than the pressure of oil from the main hydraulic drive by a predetermined amount. Thus, an ordinary pressure control signal is applied to the main hydraulic drive to perform an ordinary pressure control. However, through modification of the pressure control signal applied to the auxiliary hydraulic drive source and adjustment of a control valve, the pressure of oil from the auxiliary hydraulic drive source at the merge point becomes lower than the pressure of oil from the main hydraulic drive source at the merge point by a predetermined amount, so that pressure oscillation phenomenon (resonance phenomenon) is prevented.