Title:
HYDRAULIC DRIVE DEVICE OF WORKING MACHINE
Document Type and Number:
WIPO Patent Application WO/2012/111525
Kind Code:
A1
Abstract:
[Problem] To provide a hydraulic drive device of a working machine, which is capable of ensuring good operability during a normal operation and during a minor operation and reducing energy loss during the minor operation.
[Solution] The present invention has a configuration in which a controller (31) is provided with: a pump discharge amount control unit (40) which performs control processing in which when the operation mode of a working element operation device is an operation mode regarded as a minor operation, a control signal for making the displacement of a variable capacity hydraulic pump (10) smaller than a displacement corresponding to a normal operation is outputted to a control unit of an electromagnetic proportional pressure reducing valve (21); and a center bypass valve control unit (50) which performs control processing in which when the operation mode is an operation mode regarded as the minor operation and the load pressure of a working element actuator is low, a control signal for making the amount of opening relatively larger while a center bypass valve (22) is in a state of switching between a fully open position and a fully closed position is outputted to a control unit of a proportional electromagnetic valve (23).
Inventors:
KAYANE MASAHIRO (JP)
ICHIMURA KAZUHIRO (JP)
KODAKA KATSUAKI (JP)
ICHIMURA KAZUHIRO (JP)
KODAKA KATSUAKI (JP)
Application Number:
PCT/JP2012/052977
Publication Date:
August 23, 2012
Filing Date:
February 09, 2012
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACHINERY (JP)
KAYANE MASAHIRO (JP)
ICHIMURA KAZUHIRO (JP)
KODAKA KATSUAKI (JP)
KAYANE MASAHIRO (JP)
ICHIMURA KAZUHIRO (JP)
KODAKA KATSUAKI (JP)
International Classes:
F15B11/02; E02F9/22; F15B11/00
Foreign References:
| JPH1018359A | 1998-01-20 | |||
| JPH10103306A | 1998-04-21 | |||
| JPH11303809A | 1999-11-02 | |||
| JP2010230039A | 2010-10-14 | |||
| JP2011085159A | 2011-04-28 | |||
| JP2011127727A | 2011-06-30 | |||
| JPH1182416A | 1999-03-26 |
Other References:
See also references of EP 2677180A4
Attorney, Agent or Firm:
The Patent Body Corporate TAKEWA INTERNATIONAL PATENT OFFICE (JP)
Patent business corporation Takekazu international patent firm (JP)
Patent business corporation Takekazu international patent firm (JP)
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Claims: