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:
Feb. 02, 2021
Filed:
Aug. 05, 2019
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Yoshifumi Takimoto, Ibaraki, JP;
Kazuo Takiguchi, Ibaraki, JP;
Chinori Iio, Ibaraki, JP;
Jun Okamura, Ibaraki, JP;
Hiromasa Takahashi, Chiba, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
There is provided a hydraulic drive device for a working machine with which a number of times of maintenance can be reduced. A controller () opens a first on-off valve (), closes a second on-off valve (), switches a first directional switching valve () to a first position (A), and switches a second directional switching valve () to a third position (C), thereby pressure oil from a hydraulic pump () is supplied from the first on-off valve to an actuator () through the first directional switching valve. When history data of the first on-off valve is determined to satisfy a prescribed condition, the controller closes the first on-off valve, opens the second on-off valve, switches the first directional switching valve to a second position (B), and switches the second directional switching valve to a fourth position (D), thereby pressure oil from the hydraulic pump is supplied from the second on-off valve to the actuator through the second directional switching valve. For example, the controller determines that the prescribed condition is satisfied when an operation number of times of the first on-off valve reaches a first prescribed value.