Title:
SERVOASSIST OF SPOOL VALVE
Document Type and Number:
Japanese Patent JPS5874981
Kind Code:
A
Abstract:
PURPOSE:To stably operate a servoassist without being badly influenced by a back pressure by introducing the pressurized oil into a servoactuator interlocked with an output shaft through a selector valve in which the both edges of a spool is opened to the air. CONSTITUTION:When a rod 72 is moved rightward, a rod 67 is not moved but a spool 62 is moved, because a spool 51 is kept at a neutral position by a strong spring 54. Both oil chambers 74 and 75b are allowed to communicate through the transition described the above, and the pressurized oil discharged from an oil hydraulic pump is fed into the oil chamber 80b in a servocylider 63, and a servopiston 64 is moved rightward. When the rod 72 is moved leftward, the spool 62 is shifted leftward to feed the pressurized oil into the oil chamber 80 of a servocylinder 63, and the servo piston 64 is moved leftward in response to the amount of transfer of the rod 72, and when a certain amount of transfer is reached, the servopiston 64 stops similarly in the case of the rightward transfer of the rod 72.
Inventors:
YOSHIDA KUNIHIKO
NOZAWA YUUSAKU
NOZAWA YUUSAKU
Application Number:
JP17294281A
Publication Date:
May 06, 1983
Filing Date:
October 30, 1981
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACHINERY
International Classes:
F16K31/12; F16K31/124; (IPC1-7): F16K31/124
Attorney, Agent or Firm:
Kenjiro Take