Title:
FLUID PRESSURE CONTROL DEVICE
Document Type and Number:
WIPO Patent Application WO/2020/044701
Kind Code:
A1
Abstract:
A fluid pressure control device (100) comprises, a control valve (31) that switches between delivering and discharging hydraulic fluid to and from a boom cylinder (10) in accordance with pilot pressure of a pilot chamber (32a), a first main drain passage (170a) through which flows hydraulic fluid discharged from the first pilot chamber (32a) through a first pilot pressure control valve (71), and a load-holding mechanism (40) interposed in a first main passage (24) connecting the control valve (31) and a counter-rod-side chamber (20b) of the boom cylinder (10). The load-holding mechanism (40) has a valve body (42) capable of blocking off the first main passage (24), a switching valve (46) that switches between delivering and discharging hydraulic fluid to and from a back-pressure chamber (43) set apart on the back surface of the valve body (42), and a sub-drain passage (51) through which flows hydraulic fluid discharged from the back-pressure chamber (43) through the switching valve (46), the sub-drain passage (51) being connected to the first main drain passage (170a).
Inventors:
MATSUZAKI KEIICHI (JP)
FUKUSHIMA RYO (JP)
FUKUSHIMA RYO (JP)
Application Number:
PCT/JP2019/022001
Publication Date:
March 05, 2020
Filing Date:
June 03, 2019
Export Citation:
Assignee:
KYB CORP (JP)
International Classes:
F15B11/08; F15B11/00
Domestic Patent References:
| WO2015037433A1 | 2015-03-19 | |||
| WO2015049828A1 | 2015-04-09 | |||
| WO2007069748A1 | 2007-06-21 |
Foreign References:
| JPH0442901U | 1992-04-13 | |||
| JP2007263142A | 2007-10-11 | |||
| JP2008524526A | 2008-07-10 |
Attorney, Agent or Firm:
GOTOH & PARTNERS (JP)
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