Title:
CONSTRUCTION MACHINE
Document Type and Number:
WIPO Patent Application WO/2021/090627
Kind Code:
A1
Abstract:
Provided is a construction machine in which a hydraulic actuator is driven by a closed-circuit hydraulic pump, and with which a shortage of oil film in the closed-circuit hydraulic pump can be prevented, reliability can be improved, and a high utilization rate can be obtained. This construction machine comprises a switching valve that is provided in a branch oil passage connecting a charge line and one suction/discharge port of the closed-circuit pump, and that opens and closes in response to a control signal from a controller. When a state in which the capacity of the closed-circuit pump is held at zero continues for a prescribed amount of time or longer, the controller opens the switching valve and holds the capacity of the closed-circuit pump at not less than a prescribed capacity which is greater than zero.
Inventors:
HIRAKU KENJI (JP)
NAKAYAMA AKIRA (JP)
SAITOH TEPPEI (JP)
NAKAYAMA AKIRA (JP)
SAITOH TEPPEI (JP)
Application Number:
PCT/JP2020/037923
Publication Date:
May 14, 2021
Filing Date:
October 06, 2020
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACH CO (JP)
International Classes:
F15B11/00; E02F9/22; F15B11/02; F15B11/08
Foreign References:
| JP2000161312A | 2000-06-13 | |||
| JPS58144104U | 1983-09-28 | |||
| JPS5940602U | 1984-03-15 | |||
| JP2015048899A | 2015-03-16 |
Other References:
See also references of EP 4006358A4
Attorney, Agent or Firm:
KAICHI IP (JP)
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