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Patent Searching and Data


Title:
LIQUID PRESSURE SERVO DEVICE
Document Type and Number:
Japanese Patent JPH084703
Kind Code:
A
Abstract:

PURPOSE: To secure a certain oil quantity even during a power failure, etc., so as to perform a specified function by constructing a liquid pressure servo device in such a manner that the neutral point of a control valve for outputting a liquid pressure supplied from a liquid pressure source according to a signal quantity from a current amplifier is offset and an output from the current amplifier is also offset.

CONSTITUTION: A liquid servo device supplies pressure oil produced by means of an oil pressure unit 1 to a hydraulic cylinder 2 via an oil pressure accumulator 3 and an electric oil servo valve 4. The electric oil servo valve 4 is controlled by means of a comparator 7 for obtaining a deviation between a detection signal and a control signal from a displacement detector 6 provided in the hydraulic cylinder 2 and a control equipment 8 having an amplifier 5. In this case, the servo valve 4 is adjusted so as to provide the neutral point with a fixed offsetting quantity and the amplifier 5 is so constracted as having an offset for canceling the offset thereof. Thus, during the power failure the servo valve 4 functions as a throttle by offsetting and by securing a fixed oil quantity the hydraulic cylinder 2 can be moved.


Inventors:
KAWACHI HIROMITSU
Application Number:
JP13880194A
Publication Date:
January 09, 1996
Filing Date:
June 21, 1994
Export Citation:
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Assignee:
SHIMADZU CORP
International Classes:
F15B9/09; (IPC1-7): F15B9/09
Attorney, Agent or Firm:
Kazuhiro Akazawa