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Title:
CIRCUIT PRESSURE HOLDING DEVICE FOR HYDRAULIC CLOSING CIRCUIT
Document Type and Number:
Japanese Patent JP3668543
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To perform non-smooth operation of a hydraulic actuator due to abnormal reduction of a circuit pressure during movement of an object when an object having high inertia is moved from a stop state by the hydraulic actuator.
SOLUTION: A hydraulic circuit is constituted in such a manner that the ports 1a and 1b of a hydraulic pump 1 are communicated with the ports 3a and 3b, having different pressure receiving areas, of a hydraulic actuator 3 through lines 4 and 5. Discharge of a surplus flow rate and supply of an insufficient flow rate, occurring to the lines 4 and 5 due to operation of a hydraulic pump 1, are effected by control valves 6 and 7 to which pilot pressures in the lines 5 and 4 are guided. In this case, by inserting a pair of check valves 11 and 12, different in a flow direction, in parallel in the line 4, the flows of the lines 4 and 5 form a flow accompanied by a cracking pressure to prevent abnormal reduction of a circuit pressure, and the control valves 6 and 7 are stabilized to smooth operation of the hydraulic actuator 3.


Inventors:
Hiyoudou, Norikazu
Machida, Tetsuji
Application Number:
JP1995000328840
Publication Date:
July 06, 2005
Filing Date:
December 18, 1995
Export Citation:
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Assignee:
TOKIMEC INC
International Classes:
F15B7/10; F15B11/028; F15B11/08; (IPC1-7): F15B11/08
Domestic Patent References:
JP60219198A
JP6081501A
JP480902U
JP50077688U
JP50077689U
Attorney, Agent or Firm:
大澤 敬