Title:
HYDRAULIC DRIVE DEVICE FOR WORKING VEHICLE
Document Type and Number:
WIPO Patent Application WO/2018/180323
Kind Code:
A1
Abstract:
Provided is a hydraulic drive device for a working vehicle, the hydraulic drive device being configured to reduce impact on an operator who operates an actuator. This hydraulic drive device for a working vehicle comprises: a variable displacement or fixed displacement main pump (1) for discharging pressurized oil; a main flow passage (F1) for supplying to an actuator the pressurized oil discharged from the main pump; a fixed displacement sub-pump (5) for discharging pressurized oil; a sub-flow passage (F2) for causing the pressurized oil discharged from the sub-pump to flow into the main flow passage and supplying the oil to an actuator (2); a flow combining switching valve (6A) for connecting or disconnecting the main flow passage and the sub-flow passage; a controller (30) for controlling the operation of the flow combining switching valve; and a relief valve (7A) provided in the sub-flow passage. The relief valve has pressure override characteristics which tend to cause a relief pressure to increase from a cracking pressure to a set pressure as a relief flow rate increases.
Inventors:
TANAKA SHINICHIRO (JP)
Application Number:
PCT/JP2018/008864
Publication Date:
October 04, 2018
Filing Date:
March 07, 2018
Export Citation:
Assignee:
KCM CORP (JP)
International Classes:
F15B11/02; E02F9/22; F15B11/028
Foreign References:
| JP2006083990A | 2006-03-30 | |||
| JPH10266274A | 1998-10-06 |
Other References:
See also references of EP 3492753A4
Attorney, Agent or Firm:
THE PATENT BODY CORPORATE TAKEWA INTERNATIONAL PATENT OFFICE (JP)
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