Title:
HYDRAULIC CONTROL CIRCUIT FOR WORK MACHINE
Document Type and Number:
Japanese Patent JP2020133726
Kind Code:
A
Abstract:
To attain reduction of fuel consumption and improvement of operability and to accurately perform pump pressure control through opening area control of a bypass valve regardless of a condition at every control in a hydraulic control circuit comprising a bypass oil path which is formed while being branched from a discharge line of a hydraulic pump and reaches an oil tank, and the bypass valve of which the opening area is variable so as to control a flow rate of the bypass oil path.SOLUTION: When non-manipulating a manipulator 7, closed loop control is performed on an opening area of a bypass valve 11 in such a manner that a pump pressure is maintained at a preset pressure. When manipulating the manipulator 7, on the other hand, open loop control is performed to decrease the opening area of the bypass valve 11 in accordance with a manipulated variable of the manipulator. A correspondence between the manipulated variable of the manipulator in the open loop control and the opening area of the bypass valve 11 is corrected based on the opening area of the bypass valve 11 during the closed loop control.SELECTED DRAWING: Figure 5
Inventors:
NAKAJIMA HIDEKI
Application Number:
JP2019026298A
Publication Date:
August 31, 2020
Filing Date:
February 18, 2019
Export Citation:
Assignee:
CATERPILLAR SARL
International Classes:
F15B11/00; E02F9/20
Domestic Patent References:
| JPH109204A | 1998-01-13 | |||
| JPH09105402A | 1997-04-22 |
Attorney, Agent or Firm:
Tetsuo Hirose
Suzuki Yuko
Hirose Ikuo
Suzuki Yuko
Hirose Ikuo