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. 29, 2022
Filed:
Jul. 24, 2019
Kobe Steel, Ltd., Kobe, JP;
Kobelco Construction Machinery Co., Ltd., Hiroshima, JP;
Kobe Steel, Ltd., Kobe, JP;
KOBELCO CONSTRUCTION MACHINERY CO., LTD., Hiroshima, JP;
Abstract
A hydraulic drive apparatus includes a boom flow rate control valve, a target boom cylinder speed calculation part calculating a target boom cylinder speed for making a construction surface by a bucket closer to a target construction surface based on the cylinder speed of a boom cylinder and the like, and a boom flow rate operation part. The boom flow rate operation part operates the boom flow rate control valve to make a boom cylinder supply flow rate be a target supply flow rate corresponding to the target boom cylinder speed when the target boom cylinder speed direction coincides with a cylinder thrust direction, and operates the boom flow rate control valve to make the boom cylinder discharge flow rate be a target discharge flow rate corresponding to the target boom cylinder speed when the target boom cylinder speed direction is opposite to the cylinder thrust direction.