Title:
HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINE
Document Type and Number:
WIPO Patent Application WO/2014/054326
Kind Code:
A1
Abstract:
A hydraulic circuit for a construction machine controls the operation of hydraulic actuators. The hydraulic circuit is provided with: a detection means which detects the first drive pressure of pressurized oil supplied to one hydraulic actuator and also detects the second drive pressure of pressurized oil supplied to the other actuator; a recycling circuit which re-supplies return oil returned from the one hydraulic actuator; and a control means which controls a hydraulic pump, the detection means, and the recycling circuit. The recycling circuit has a recycling valve in a hydraulic passage for re-supplying the return oil. The control means is provided with a pressure difference calculation unit for calculating the difference in pressure between hydraulic pressure upstream of the recycling valve and hydraulic pressure downstream of the recycling valve on the basis of the difference in load pressure between the first drive pressure and the second drive pressure. The control means controls the degree of opening of the recycling valve on the basis of the calculated pressure difference.
Inventors:
ISHIYAMA HIROSHI (JP)
Application Number:
PCT/JP2013/068898
Publication Date:
April 10, 2014
Filing Date:
July 10, 2013
Export Citation:
Assignee:
SUMITOMO HEAVY INDUSTRIES (JP)
International Classes:
F15B11/024; E02F9/22; F15B11/028; F15B21/14
Domestic Patent References:
| WO2002086331A1 | 2002-10-31 |
Foreign References:
| JPH0289050U | 1990-07-13 | |||
| JP2007023606A | 2007-02-01 |
Attorney, Agent or Firm:
ITOH, Tadashige et al. (JP)
Tadashige Ito (JP)
Tadashige Ito (JP)
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