Title:
BOOM DRIVE DEVICE FOR CONSTRUCTION MACHINE
Document Type and Number:
WIPO Patent Application WO/2013/175699
Kind Code:
A1
Abstract:
Provided is a device for driving the boom of a construction machine, the device requiring reduced power. This construction machine is provided with: a boom cylinder (6); a variable displacement hydraulic pump (10); a control valve (12) for conducting oil, which is discharged from the hydraulic pump (10), to the boom cylinder (6); a boom raising operation detector (42) for detecting boom raising operation; boom cylinder pressure detectors (46A, 46B); a supply switching valve (30) capable of being switched between a permitting position at which the supply of hydraulic oil from the hydraulic pump (10) to the head-side chamber (6a) of the boom cylinder (6) is permitted and a blocking position at which the supply is blocked; a replenishment oil passage (34) for permitting the replenishment of hydraulic oil to the head-side chamber (6a) when the hydraulic oil supply from the hydraulic pump (10) to the head-side chamber (6a) is blocked; and a controller (50) which, upon determining that excavation reaction force is at a level which allows the boom cylinder (6) to extend even if there is no supply of hydraulic oil from the hydraulic pump (10) to the head-side chamber (6a) in boom raising operation, sets the supply switching valve (30) to the blocking position and reduces the displacement of the hydraulic pump (10).
More Like This:
| WO/2004/070211 | HYDRAULIC WORKING MACHINE |
| WO/2007/126310 | LIFTING SYSTEM |
Inventors:
UEDA KOJI
TAJIMA KAZUHARU
TAJIMA KAZUHARU
Application Number:
PCT/JP2013/002468
Publication Date:
November 28, 2013
Filing Date:
April 11, 2013
Export Citation:
Assignee:
KOBELCO CONSTR MACH CO LTD (JP)
International Classes:
E02F9/22; F15B11/00; F15B11/02
Domestic Patent References:
| WO2004005727A1 | 2004-01-15 | |||
| WO2004005727A1 | 2004-01-15 |
Foreign References:
| JP2012172491A | 2012-09-10 | |||
| JP2011017135A | 2011-01-27 | |||
| JP2010190261A | 2010-09-02 |
Other References:
See also references of EP 2857695A4
Attorney, Agent or Firm:
KOTANI, Etsuji et al. (JP)
Etsuji Kotani (JP)
Etsuji Kotani (JP)
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