Title:
FLUID PRESSURE CIRCUIT
Document Type and Number:
WIPO Patent Application WO/2002/086331
Kind Code:
A1
Abstract:
When boom lowering operation for operating a boom cylinder (6) by an external load (W) and an arm cylinder (26) or a bucket cylinder (27) are interlocked in the air, a first changeover valve for boom (2) is controlled to neutral position and a boom regeneration valve (13) is controlled to open position. Since working oil is regenerated from a line (9) on the working oil return side of the boom cylinder (6) through the boom regeneration valve (13) to a line (5) on the working oil supply side, the working oil supply from a hydraulic source (4) to the boom cylinder (6) is not required and a larger quantity of working oil can be supplied from the hydraulic source (4) through a second changeover valve for arm (24) or a changeover valve for bucket (25) to the arm cylinder (26) or the bucket cylinder (27). Working speed of the arm cylinder (26) or the bucket cylinder (27) can thereby be increased and work efficiency of a hydraulic shovel can be enhanced at the time of interconnecting operation.
Inventors:
SHIMADA YOSHIYUKI (JP)
Application Number:
PCT/JP2002/001136
Publication Date:
October 31, 2002
Filing Date:
February 12, 2002
Export Citation:
Assignee:
CATERPILLAR MITSUBISHI LTD (JP)
SHIMADA YOSHIYUKI (JP)
SHIMADA YOSHIYUKI (JP)
International Classes:
E02F9/22; F15B11/024; F15B11/17; F15B21/14; (IPC1-7): F15B21/14
Foreign References:
| JPH09132927A | 1997-05-20 | |||
| JPS5549116U | 1980-03-31 | |||
| JPS4536432B1 | 1970-11-19 | |||
| JPH0254902U | 1990-04-20 | |||
| JP2000309952A | 2000-11-07 | |||
| JPH09132927A | 1997-05-20 | |||
| US6092454A | 2000-07-25 |
Other References:
See also references of EP 1380756A4
Attorney, Agent or Firm:
Kabasawa, Joo (Shinjuku 3-chome Shinjuku-ku, Tokyo, JP)
Download PDF: