HYDRAULIC DRIVE DEVICE OF CONSTRUCTION MACHINE

WIPO Patent Application WO/2013/153984

A1

A pressure compensation valve that does not fully close at stroke end is used and a travel operation is performed, whereupon pilot primary pressure is reduced and supplied to the remote control valves (34c-34h) of a non-travel operation device. The inflow of pressure oil to a non-travel actuator in a travel composite operation is thereby suppressed, and a travel motor is ensured the necessary amount of pressure oil. When there is saturation in a composite operation such that there is a large difference between the load pressure of two actuators in the hydraulic drive device of a construction machine in which load sensing control is performed, the pressure compensation valve having the lower load pressure is thereby prevented from closing to prevent deceleration or stopping of the actuator having the lower load pressure, the actuator having the higher load pressure is ensured to have the necessary amount of pressure oil to prevent deceleration or stopping of the higher-load-pressure actuator, and satisfactory composite operability is achieved.

JP5404597	Hydraulic work machine
JPS6479405	HYDRAULIC CONTROL SYSTEM
JP2004100366	SHOCK DAMPING DEVICE IN STARTING/STOPPING ROLLING VEHICLE

TAKEBAYASHI YOSHIFUMI (JP)
TAKAHASHI KIWAMU (JP)
MORI KAZUSHIGE (JP)
NAKAMURA NATSUKI (JP)

PCT/JP2013/059946

October 17, 2013

April 01, 2013

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HITACHI CONSTRUCTION MACHINERY (JP)

F15B11/08; E02F9/22; F15B11/02; F15B11/05

JPH0776861A	1995-03-20
JP2009167618A	2009-07-30
JPH04370402A	1992-12-22
JP2010047983A	2010-03-04
JP2003156006A	2003-05-30
JP2007024103A	2007-02-01
JPH0776861A	1995-03-20

See also references of EP 2837831A4

KASUGA Yuzuru (JP)
Kasuga 讓 (JP)

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