CONSTRUCTION-MACHINE HYDRAULIC CONTROL DEVICE - HITACHI CONSTRUCTION MACH CO

Title:

CONSTRUCTION-MACHINE HYDRAULIC CONTROL DEVICE

Document Type and Number:

WIPO Patent Application WO/2016/194783

Kind Code:

A1

Abstract:

Provided is a construction-machine hydraulic control device that can reduce meter-out pressure loss in accordance with changes in a negative load acting on a hydraulic actuator, and that can prevent a deterioration of operability even if a malfunction occurs in a pressure sensor for detecting the magnitude of the negative load. The device comprises the following: a meter-out flow path in which flows pressure oil that is discharged from the hydraulic actuator; a variable aperture provided to the meter-out flow path; a load detector for detecting the magnitude of a negative load which is a load that can be added to the hydraulic actuator by an external force, and which is a load in the same direction as the operation direction of the hydraulic actuator; and a control device for, when a malfunction is not detected in the load detector, reducing the total value of the open area of the variable aperture in accordance with an operation amount of an operation amount detector and an increase in the magnitude of the negative load detected by the load detector, and for, when a malfunction has been detected in the load detector, reducing the total value of the open area of the variable aperture to a value determined beforehand, in accordance with the operation amount of the operation amount detector.

Inventors:

YAMASHITA RYOHEI (JP)
IMURA SHINYA (JP)
ISHIKAWA KOUJI (JP)
MORIKI HIDEKAZU (JP)
AMANO HIROAKI (JP)

Application Number:

PCT/JP2016/065643

Publication Date:

December 08, 2016

Filing Date:

May 26, 2016

Export Citation:

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Assignee:

HITACHI CONSTRUCTION MACH CO (JP)

International Classes:

F15B20/00; E02F9/22; F15B11/04; F15B11/08

Foreign References:

JP2004076904A	2004-03-11
JPH1195855A	1999-04-09

Other References: