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:
Oct. 13, 2020
Filed:
Mar. 24, 2017
Tadano Ltd., Kagawa, JP;
TADANO LTD., Kagawa, JP;
Abstract
The unload circuit includes a pump oil passage that connects between a hydraulic pump and a direction control valve, a tank oil passage that connects between the direction control valve and a hydraulic tank, a pressure compensating flow control valve interposed between the pump oil passage and the tank oil passage, a pilot operated relief valve interposed between the pump oil passage and the tank oil passage, and an unloading solenoid valve interposed in a vent oil passage of the pilot operated relief valve. The failure diagnosis device includes a pressure sensor that measures a pressure of the pump oil passage, and a controller that receives a pressure signal from the pressure sensor. The controller performs failure diagnosis of the unload circuit based on a differential pressure between a first pump oil passage pressure during unloading and a second pump oil passage pressure during on-loading.