Title:
OIL PRESSURE CLOSED CIRCUIT FOR DRIVING ACTUATOR
Document Type and Number:
Japanese Patent JPS58102806
Kind Code:
A
Abstract:
PURPOSE:To enable to prevent an occurrence of energy loss and cavitation of the oil pressure closed circuit for driving actuator by a method wherein a charge pump comprises a capacity variable oil pressure pump which is controlled in accordance with the pressure of a main circuit on a low pressure side. CONSTITUTION:The charge pump 11 comprises a capacity variable oil prssure pump. A displacement volume variable mechanism 12 of the capacity variable charge pump 11 is controlled by a control cylinder 13. The control cylinder 13 includes a pilot pipe 17 to connect a pressure chamber 16 and the discharge side of the capacity variable charge pump. With such a construction, when the pressure of the main circuits 2A and 2B on the low pressure side is larger than a preset pressure, the pushaway volume variable mechanism 12 is maintained at a neutral position. To the contrary, when the pressure is smaller than the preset value, the mechanism 12 is moved to a pressurized oil discharge position so that the occurrence of energy loss and cavitation in the actuator driving oil pressure circuit can be prevented effectively.
Inventors:
OOSHINA MORIO
KANAI TAKASHI
OCHIAI MASAMI
KANAI TAKASHI
OCHIAI MASAMI
Application Number:
JP20083281A
Publication Date:
June 18, 1983
Filing Date:
December 15, 1981
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACHINERY
International Classes:
F15B11/08; F15B7/00; (IPC1-7): F15B11/08
Attorney, Agent or Firm:
Kenjiro Take
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