Title:
VALVE DEVICE
Document Type and Number:
WIPO Patent Application WO/1989/008213
Kind Code:
A1
Abstract:
An actuator control valve (6) is fitted on a hydraulic machine having a hydraulic pump (1) and a hydraulic actuator (2) driven by a pressure oil discharged from this hydraulic pump. This valve device has a meter-in circuit (4) adapted to introduce the pressure oil discharged from the hydraulic pump into the actuator, and a meter-out circuit (5) adapted to introduce a return oil from the actuator into a tank (3). The meter-out circuit is provided with pilot circuits (24a, 24b) including a main valve (22) for controlling the return oil from the actuator, and a variable throttle means (23), which main valve is adapted to be closed when the pilot circuits are closed, and to vary the degree of opening of itself in accordance with the throttling rate of the variable throttle means, and control means (27-31) adapted to vary the throttling rate of the variable throttle means in accordance with the driving pressure of the actuator.
Inventors:
SUGIYAMA GENROKU (JP)
HIRATA TOICHI (JP)
TANAKA HIDEAKI (JP)
YUASA KAZUMASA (JP)
NOZAWA YUSAKU (JP)
HIRATA TOICHI (JP)
TANAKA HIDEAKI (JP)
YUASA KAZUMASA (JP)
NOZAWA YUSAKU (JP)
Application Number:
PCT/JP1989/000184
Publication Date:
September 08, 1989
Filing Date:
February 23, 1989
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACHINERY (JP)
International Classes:
F15B11/00; F15B13/04; F16K15/18; (IPC1-7): F16K17/04; F15B11/02
Foreign References:
| JPS61186804U | 1986-11-21 | |||
| JPS5329912Y2 | 1978-07-26 | |||
| JPS5920881B2 | 1984-05-16 | |||
| JPS55631B2 | 1980-01-09 |
Other References:
See also references of EP 0354972A4
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