Title:
HYDRAULIC SYSTEM
Document Type and Number:
WIPO Patent Application WO/2017/164371
Kind Code:
A1
Abstract:
Provided is a hydraulic system with which an operator can safely perform work during an emergency operation even in the event that an electromagnetic proportional valve has failed. This hydraulic system is provided with a hydraulic pump, a control valve, and a pilot pressure supply unit. The pilot pressure supply unit has: an electromagnetic proportional valve that has a detent-type emergency manual operation function with which a pilot oil passage can be opened manually and generates pilot pressure for a control valve; a controller that controls the degree of opening of the electromagnetic proportional valve in accordance with the operation of an operation lever; and a pilot pressure switching unit that switches the oil pressure state of the pilot pressure supply unit between an on-loading state or an unloading state. The pilot pressure switching unit performs controls to implement the unloading state when the electromagnetic proportional valve is being opened manually and performs control to implement the on-loading state after the electromagnetic proportional valve has been opened manually.
Inventors:
KAWABUCHI NAOTO
YOSHIDA NAOFUMI
MASUDA NAOTAKA
FUKUMORI YASUHIRO
YOSHIDA NAOFUMI
MASUDA NAOTAKA
FUKUMORI YASUHIRO
Application Number:
PCT/JP2017/012021
Publication Date:
September 28, 2017
Filing Date:
March 24, 2017
Export Citation:
Assignee:
TADANO LTD (JP)
International Classes:
F15B20/00; B66C15/00
Foreign References:
| JP2003184810A | 2003-07-03 | |||
| JPH09310782A | 1997-12-02 | |||
| JPH07127608A | 1995-05-16 | |||
| JP2000344466A | 2000-12-12 |
Other References:
See also references of EP 3434913A4
Attorney, Agent or Firm:
WASHIDA, Kimihito (JP)
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