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Patent Searching and Data


Title:
HYDRAULIC DRIVE SYSTEM FOR CONSTRUCTION MACHINE
Document Type and Number:
WIPO Patent Application WO/2018/043401
Kind Code:
A1
Abstract:
This hydraulic drive system is provided with: a hydraulic actuator; a control valve for controlling the supply and discharge of hydraulic oil to and from the hydraulic actuator; a pilot operation valve connected to an operation valve by a pair of pilot lines; an electromagnetic proportional pressure reducing valve provided to at least one of the pair of pilot lines; an operation detector for outputting an operation amount signal corresponding to the tilt angle of the operation lever of the pilot operation valve; and a control device which, immediately after the amount of variation per unit time in the operation amount signal outputted from the operation detector decreases by a value exceeding or equal to a threshold value, starts to control the electromagnetic proportional pressure reducing valve so that pressure at a pilot port of the control valve will be gradually reduced to zero by the communication between the secondary pressure port of the electromagnetic proportional pressure reducing valve and the tank port thereof.

Inventors:
KONDO, Akihiro
MURAOKA, Hideyasu
UMEKAWA, Jun
Application Number:
JP2017/030742
Publication Date:
March 08, 2018
Filing Date:
August 28, 2017
Export Citation:
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Assignee:
KAWASAKI JUKOGYO KABUSHIKI KAISHA (1-1 Higashikawasaki-cho 3-chome, Chuo-ku Kobe-sh, Hyogo 70, 〒6508670, JP)
International Classes:
F15B11/00; E02F9/20; E02F9/22; F15B11/08
Foreign References:
JPH08177085A1996-07-09
JPH09235756A1997-09-09
Attorney, Agent or Firm:
PATENT CORPORATE BODY ARCO PATENT OFFICE (3rd Fl, Bo-eki Bldg. 123-1, Higashimachi, Chuo-ku, Kobe-sh, Hyogo 31, 〒6500031, JP)
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