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. 30, 2021
Filed:
Sep. 13, 2017
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Takaaki Chiba, Kasumigaura, JP;
Hiroyuki Yamada, Hitachinaka, JP;
HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo, JP;
Abstract
A work machine is provided. The work machine includes a changeover valve capable of disabling area limiting control by bypassing an area limiting control solenoid proportional valve disposed in a pilot line through which pilot pressure generated by a hydraulic pilot type operation device is guided to a directional control valve and the work machine can perform the area limiting control while ensuring response of a work implement. When a first fluid temperature Tis higher than a first predetermined temperature Ta and a control changeover switchspecifies disabling of the area limiting control, a controller brings a plurality of changeover valves into a bypass position. When the first fluid temperature Tis equal to or lower than the first predetermined temperature Ta, the controller brings the changeover valves into a communication position and places the solenoid proportional valves in a fully open position.