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. 10, 2015
Filed:
Feb. 02, 2011
Yasuo Okano, Tsuchiura, JP;
Tsuyoshi Nakamura, Tsuchiura, JP;
Kouji Ishikawa, Kasumigaura, JP;
HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo, JP;
Abstract
During a swing start, a pump torque calculating section associated with pump delivery pressure, a pump torque calculating section associated with swing operation pressure, and a maximum value selecting section of a controller perform control to change a maximum absorption torque of a second hydraulic pump between Tb and Tc in accordance with a delivery pressure of the second hydraulic pump. In an operation combining swing with other motion, a subtraction section performs a calculation to subtract a maximum absorption torque Tpof the second hydraulic pump from a total pump torque Trto thereby distribute an amount of torque reduced in the second hydraulic pump to a first hydraulic pump associated with an actuator other than a swing motor. Further, a required flow rate can be supplied to the swing motor, thus achieving a smooth shift to a constant speed swing.