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:
Mar. 10, 2020
Filed:
Sep. 29, 2015
Hitachi Construction Machinery Co., Ltd., Taito-ku, Tokyo, JP;
Seiji Hijikata, Tsukuba, JP;
Kouji Ishikawa, Kasumigaura, JP;
Takatoshi Ooki, Kasumigaura, JP;
Shinya Imura, Toride, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A hydraulic fluid energy regeneration apparatus of a work machine includes: a regeneration hydraulic motor driven by a return hydraulic fluid; a first hydraulic pump mechanically connected to the regeneration hydraulic motor; a second hydraulic pump that delivers a hydraulic fluid for driving a hydraulic actuator; a confluence line that causes the hydraulic fluid delivered from the first hydraulic pump to join the hydraulic fluid delivered from the second hydraulic pump; a first adjuster configured to adjust the flow rate of the hydraulic fluid of the first hydraulic pump; and a second adjuster configured to adjust the delivery flow rate of the second hydraulic pump. A control device includes: a first calculation section configured to calculate a non-confluence time pump flow rate in the case where the hydraulic actuator is driven solely by the second hydraulic pump and calculate a control command output to the first adjuster such that the flow rate of the hydraulic fluid from the first hydraulic pump is equal to or lower than the non-confluence time pump flow rate; and a second calculation section configured to calculate a target pump flow rate by subtracting from the non-confluence time pump flow rate the flow rate of the hydraulic fluid from the first hydraulic pump and calculate a control command output to the second adjuster such that the target pump flow rate is attained.