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. 16, 2023
Filed:
Nov. 08, 2019
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Takaaki Tanaka, Tsuchiura, JP;
Kazunori Ishihara, Tsuchiura, JP;
Jun Ikeda, Tsuchiura, JP;
Juri Shimizu, Tokyo, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
An engine () drives a variable capacity-type hydraulic pump (), discharged hydraulic oil is selectively supplied to a cooling fan () and a hoist cylinder () in accordance with switching of a selection valve (), thereby controlling the same on the basis of each target value. A pump discharge pressure (Pp) of the hydraulic oil discharged from the hydraulic pump () and a motor supply pressure (Pm) of the hydraulic oil supplied to a hydraulic motor () via the selection valve () are detected by sensors () and are compared with pressure determination values stored in advance as a pump discharge pressure (Pp) and an actuator supply pressure (Pm) generated when the target value is achieved. Presence/absence of abnormality in the hydraulic actuator control device () is determined on the basis of a result of the comparison, and when abnormality is determined to have occurred, control is performed to minimize the capacity of the hydraulic pump ().