HYDRAULIC DRIVE DEVICE FOR CONSTRUCTION MACHINE - HITACHI CONSTRUCTION MACHINERY

Title:

HYDRAULIC DRIVE DEVICE FOR CONSTRUCTION MACHINE

Document Type and Number:

WIPO Patent Application WO/2013/031768

Kind Code:

A1

Abstract:

A hydraulic drive device for performing load sensing control. The hydraulic drive device fulfills the same function as devices provided with an unload valve, recovers the energy of hydraulic oil discharged to a tank from a main pump, and effectively uses the energy of hydraulic oil generated at the main pump. A hydraulic motor (52) is disposed on a control oil path (51) for connecting a tank (T) with a second hydraulic oil supply path (4a) which supplies the discharge oil from a main pump (2) to flow control valves (26a to 26h). A power generator (53) is connected to the rotating shaft (52a) of the hydraulic motor (52). The maximum load pressure (PLmax) is detected by means of a pressure sensor (54). A second control device (55) controls the power generation of the power generator (53) such that the hydraulic motor (52) rotates when the discharge pressure of the main pump (2) becomes higher than the target control pressure (Pun) in which a pre-set value (Pb) is added to the maximum load pressure (PLmax). The alternating-current power generated by means of the power generator (53) is stored in a battery (41).

Inventors:

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

Application Number:

PCT/JP2012/071700

Publication Date:

March 07, 2013

Filing Date:

August 28, 2012

Export Citation:

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Assignee:

HITACHI CONSTRUCTION MACHINERY (JP)
MORI KAZUSHIGE (JP)
TAKAHASHI KIWAMU (JP)
TAKEBAYASHI YOSHIFUMI (JP)
NAKAMURA NATSUKI (JP)

International Classes:

F15B21/14; E02F9/20; E02F9/22; F04B49/00; F04B49/06; F15B11/00

Foreign References:

JP2008063888A	2008-03-21
JP2005140143A	2005-06-02
JPH10205501A	1998-08-04
JPH10205501A	1998-08-04

Other References: