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:
May. 19, 2020
Filed:
Jan. 30, 2018
Hitachi Construction Machinery Tierra Co., Ltd., Shiga, JP;
Yoshifumi Takebayashi, Koka, JP;
Kiwamu Takahashi, Koka, JP;
Kazushige Mori, Koka, JP;
Natsuki Nakamura, Koka, JP;
HITACHI CONSTRUCTION MACHINERY TIERRA CO., LTD., Shiga, JP;
Abstract
Pressure compensating valves not fully closing at the stroke end are employed, and upon the operator's operation for the traveling, pilot primary pressure is reduced and supplied to remote control valves-of non-travel operating devices. Thus, the inflow of the hydraulic fluid into non-travel actuators is suppressed and a necessary amount of hydraulic fluid for travel motors is secured in travel combined operation. Accordingly, when saturation occurs in a construction machine's hydraulic drive system performing the load sensing control due to combined operation with a great load pressure difference between two actuators, deceleration/stoppage of an actuator on the low load pressure side is prevented by preventing full closure of the pressure compensating valve on the low load pressure side, while also preventing deceleration/stoppage of a high load pressure actuator by securing a necessary amount of hydraulic fluid for the high load pressure actuator.