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. 23, 2017
Filed:
Apr. 03, 2012
Nobuhisa Matsushima, Ibaraki, JP;
Nobuhisa Matsushima, Ibaraki, JP;
Bosch Rexroth Corporation, Tokyo, JP;
Abstract
There is provided a hydraulic circuit which can further improve a responsive characteristic in a pressure reducing operation and a reliability in the pressure reducing operation of a relief valve device, when a main circuit pressure exceeds a predetermined pressure. A relief valve device for reducing the main circuit pressure in the hydraulic circuit including a hydraulic pump includes a first valve unit having a pilot spool and a pilot spring, a position of the pilot spool being determined by a balance between a throttle pressure supplied from the main circuit via a throttle oil passage and the control pressure and a biasing force of the pilot spring, and releasing the main circuit pressure outward via the throttle oil passage, and includes a second valve unit having a valve piston and a valve spring, a position of the valve piston being determined by a balance between the main circuit pressure and the throttle pressure and the biasing force of the valve spring, and releasing the main circuit pressure outward.